Topper's Choice........................

JEE IIT Cutoff 2010

2011-05-14T11:05:00.000-07:00

http://www.jee.iitk.ac.in/aggregate2010.php

IIT JEE Solution - 2011 (chemistry Paper 1)

2011-04-10T11:15:00.000-07:00

MOST FREQUENTLY ASKED QUESTIONS ON EXAMS

2011-03-21T11:24:00.000-07:00

How do I deal with exam related stress?
Recognize your negative thoughts. Once you closely examine these thoughts you'll see how unrealistic they are. Challenge the thoughts that say you are a failure and that you can't succeed. Remind yourself that it was just another exam and with effort, you will do better in your next attempt.

n What if I do badly?
Replace self-criticism with self-correction. Judging yourself harshly now won't help you do better in the future. Take the position of an observer. What if a good friend told you he had failed? Would you call him a failure? Most probably you would emphasize his good points and help him put the situation in perspective.

n How do I deal with my family's disappointment if my results are not good?
Be open and honest with them. Share what you feel about the result and what you think went wrong. Reassure them of your concern and efforts. Above all, do not have a negative bias against your parents because sometimes they need more reassuring than you do.

n What if I don't get the marks I'm expecting?
Concentrate on your achievements and be realistic about your expectations as well. Usually we know when we have made a mistake, so take these into account while drawing up expected marks. If you are still dissatisfied with the results, the option of rechecking is always open.

n We have heard of irregularities in the assessment system. What if my marks are adversely affected?
Have faith in the system. There will always be rumours about unfair checking, but one cannot ignore the fact that results over all these years have more often than not, been fair.

n I think there is too much pressure and I can't cope with it.
Take professional help. If you feel that there is pressure and you are unable to handle it and your self-esteem is coming down and you are unable to cope, then you must consult a psychiatrist to help you tide over this phase.

n Everyone tells me to concentrate on my studies.
Don't stop enjoying life. One of the common mistakes an individual makes is to totally change his lifestyle. This is under the assumption that if he isolates himself from all leisure and fun times with friends and family and only study, then he will do better.

n How much sleep is required?
The human body requires an average of 8 hours of sleep per day. But there is no hard and fast rule. Each one of us has to understand our body rhythm and know by trial and error how many hours of sleep keeps us fit.

n What happens if we sleep less than what our body requires?
If you sleep less for a day or two your body copes up by taking more sleep over next two days. If continued for long then the body gets into what is known as sleep deprivation syndrome because it accumulates so many hours of Sleep Debt. Then you get symptoms of feeling tired and sleepy, headaches, body aches, poor digestion, inability to concentrate, irritability, short tempered ness etc

n Should I study in the morning or at night?
First understand whether you are an owl or a lark. IF you can get up early in the morning and feel fresh then you must sleep early and get up early and study. If on the other hand you can study late at night but cannot feel fresh when you get up early to study then you must sleep late after studying and get up later in the morning.

n How do you get a good night sleep?
Try to keep a fixed time every night for sleeping as far as possible. Avoid afternoon prolonged sleeping, a short nap may be helpful. One hour before bed-time avoid stimulating your sensory system by too much noise like loud music, too much TV, arguments or fights. Three hours before sleep time avoid taking any food or liquids, which contain caffeine, like aerated coal drinks, drinks containing chocolate.

n To keep awake for studying students drink lots of coffee. What is the harm?
Caffeine in small doses acts as a stimulant and keeps you awake, so a cup once a day may be Ok. Excessive coffee drinking gives side effects like tremors, fast pule rate, irritability, acidity and stomach pain. Coffee also causes addiction.

n Why exercise during exam time?
Most children will say they have no time for exercise during exam days. They are already stressed out with lack of time, how can they waste time in exercise? The fact is that exercise is all the more necessary during exam time because not only is it a “stress buster “ but also has many other health benefits needed to keep fit during exam.

n What does exercise do?
God has given us our body which is a perfect machine!. But as with any a machine to keep in good running condition, it requires maintenance or it will develop problems in various parts or rust due to disuse. Similarly if all our body parts are not moved effectively, as in exercise, the body parts will fail and then you will get physical problems like lack of stamina, excessive sleep, headache, muscle pains, fatigue etc. You will also get mental problems like feeling low or depressed, inability to concentrate, poor memory etc

n What are the various forms of exercise?
Aerobic exercise, running, jogging, swimming, specific aerobic exercises, strength training, lifting weights and working on machines are some examples. Resistance or strength training increases lean body-mass which includes muscles, these in turn burn more energy daily as compared to fat mass. More muscles mean more strength and also more calories burnt, so less fat on body. Strength training helps to tone muscles and improves endurance. It reduces risk of osteoporosis so makes our bones very strong. Exercise increases co-ordination and reduces risk of injuries resulting from weak muscles.

n How does exercise help?
Regular aerobic exercise (swimming, bicycling jogging) improves the function of our cardiovascular system. This makes the circulation better, the lungs process oxygen more effectively so you have less exertion. Heart pumps blood with fewer heart beats (the athletes pulse is always slow). It stimulates the growth of capillaries that increases blood supply hence better oxygenation to muscles. All this makes your body more efficient and gives you more endurance capacity giving you more stamina for working. You can sit longer hours without discomfort. This will make you study harder and better.

n How does exercise help you be better mentally?
Regular aerobic exercise releases some good chemicals in our body. These are called endorphins. These make you feel happy. They counter the effects of stress, depression and anxiety that all students suffer from during exam time. So after exercising you get a “Natural kick” which is longer lasting and safe unlike drugs or stimulants like caffeine. It also helps you in weight loss and that will make you feel good about your self.

n What are long-term benefits of exercise?
Regular exercise will not only help you during exam but later in life you will have longer life and less risk of obesity, high blood pressure, heart attacks, diabetes, cancer and mental depression.

n Why do adolescents feel hungry all the time?
The body demands more calories during adolescence. Boys require about 2800 calories and girls about 2200 per day. Teens who are big and tall and participate in lot of physical quire more.

DO NOT MISS BREAKFAST If you miss breakfast then by the time you have lunch nearly 10 -12 hours have gone by after your last meal. This means your blood sugar level has gone and you have nothing to provide your body with energy. This low blood sugar or hypoglycemia causes short-term memory problems, difficulty in concentration problem solving.

DO NOT HAVE A VERY HEAVY DINNER You will feel very heavy and sleepy and will not be able to study well.

8. OTHER FREQUENTLY ASKED QUESTIONS

Q.1: If a student fails in the pre Board examination conducted by the school, can he/she be detained from appearing in Class X or XII Board’s exam?

Ans. No, if he/she is otherwise eligible.

Q.2: Is it possible for a student who has failed in Science stream in Class XII to change subjects to pass at subsequent examination?

Ans. Yes, but with prior permission of the Board.

Q.3: What is the eligibility criteria for a student to appear as a private candidate in Board examination?

Ans. The Board prescribes following conditions under which a candidate can appear privately: -

I. Failed candidates
II. Teachers serving in educational institutions
III. Women candidates who are bonafide residents of NCT of Delhi and
IV. Physically handicapped students

Q.4: What is the procedure of appearing in additional subject?

Ans. An additional subject may be offered within 6 years of passing the examination of the Board. The subject should be provided in the scheme of studies prescribed by the Board.

Q.5: Is it compulsory for a student to repeat the practical examination also if he/she fails in theory?

Ans. The candidate has an option to appear for practical examination again or retain the previous year practical marks for two consecutive years.

Q.6: What are the exemptions provided in examinations to physically challenged and dyslexic candidates?

Ans. Dyslexic/spastic/physically handicapped students have the option of studying one compulsory language as against two and any four subjects from the following:

I. Mathematics, II. Science, III. Social Science, IV.2nd language
(Music, Painting, Home Science and Introductory Information Technology)

i. Additional one hour (60 minutes) for each paper is provided to the students

ii. Physiotherapy exercises are considered equivalent to Physical and Health

Education

iii. Amanuensis is provided to such students.

Q.7: I wish to improve my performance in Chemistry and Maths. Is it possible and how?

Ans. A candidate who has passed Class X or XII examination of the Board may re-appear for improvement of performance in one or more subjects in the main examination in the succeeding year only. The candidate may appear privately; those re-appearing for whole examination can also appear as regular candidate if admitted by the school.

- For subjects involving practical work, if the candidate has passed the practical examination, he or she will be allowed to appear only in theory part.

Q.8: Does the Board provide any supplementary material for students preparing for X & XII examinations?

Ans. Yes, the Board publishes Sample Question Papers and marking Schemes in main subjects in Class X & XII which can be purchased from any of the Board’s offices.

Q.9: Are the questions of Sr. Sec. Exam. strictly based on NCERT books?

Ans.: NCERT books are recommended for studies as they cover the prescribed syllabus. It is, therefore, advisable to concentrate on these books.

Q.10: Is it compulsory to pass in theory and practical exams. separately?

Ans.: Yes, it is compulsory to pass separately in the subjects involving theory and practical in Class XII.

Q11: Is a student required to appear in all subjects in improvement examination?

Ans.: No, the student can appear in one or more than one subject(s) as per his/her choice. However, improvement exam. can be taken only in the successive year of passing Class X/XII exams.

Q.12: What are the kinds of questions asked in Physics, Chemistry and Biology and how should one attempt the questions?

Ans.: The Board publishes Sample Question papers in all the main subjects every year along with Marking Schemes. It is better to procure a copy of each publication. Board’s website can also be visited at cbse.nic.in

Q.13: Is there negative marking for exceeding word limit?

Ans.: No, the marks are not cut for exceeding the word limit. However, it is better to restrict to the specified word limit. This should be practiced at the time of revision, which will also help in completing the paper within the allotted time.

Q.14: How many sets of question papers are distributed in examination hall in Board’s examination?

Ans.: The Board prepares three sets of questions papers in all the main subjects having equal difficulty level.

Q.15: Is it possible to score 80% in Maths in Class X after studying from the NCERT books, latest CBSE Sample Question papers and other Sample Papers?

Ans.: Marks would entirely depend upon the preparation and performance during examination. It is, therefore, advisable to remain focused and do your best.

Q.16: Will a student lose marks if he/she opts for Hindi as a medium for writing +2 examination?

Ans.: Certainly not. The Board gives option of medium to the students to answer questions in Hindi or English and even in Urdu. The marks are deducted only in case of wrong answers.

Q.17: What are the changes in the pattern of Examination in Class XII this year?

Ans.: The changes in question paper design and weightages are mentioned in Sample Question Papers in each stream. A copy of Marking Scheme can also be bought from the Headquarter or Regional Office.

Q.18: If a student decides to drop one year, what will be the syllabus applicable for the next examination, the old or the new?

Ans.: The candidate will have to study the syllabus recommended for the year in which he/she plans to give the examination.

Q.19: What are the rules for condonation of attendance?

Ans. :I. A candidate must have 75% attendance as on 1st February of the year of examination. Shortage up to 15% may be condoned by the Chairman. Cases of candidates with attendance below 60% shall be considered for condonation of shortage of attendance only in exceptional circumstances like prolonged serious illness such as cancer, AIDS or T.B.

II Death of a parent

III. Authorized participation in sponsored tournaments and Sports meet of at least inter school level and NCC/NSS camps.

Q.20: Are marks deducted for missing steps in Maths?

Ans.: Yes, marks are deducted for missing steps. It will be better to get a copy of the Marking Scheme to know about the weightage and steps and practice accordingly.

Q.21: Is the candidate allowed to see the answer script in case the result is not as per the expectations?

Ans.: No. There is no provision of showing answer scripts. The candidate can apply for scrutiny, for reconfirmation of marks.

Q.22: If a candidate passes in the additional subject but fails in one of the main subjects, what will the result show?

Ans.: The candidate will be considered as having passed the examination in such a case. A language will replace a language only. For further details the scheme of examinations and bye-laws can be referred to.

Q.23: Is it compulsory to use ink pen for writing answers in Board exams?

Ans.: Always use blue or royal blue ink pen while writing the answers. Also try to write in neat and legible handwriting.

Q.24: How can one get good marks in Maths? Are there any guess papers published by the Board?

Ans.: The preparation in Maths essentially depends upon written practice and revising the entire syllabus. Try to solve each and every problem given in the exercises in NCERT textbook. The Board does not publish any guess papers. It will be better to practice from the Sample Question papers.

Q.25: Will the question paper of Maths be different than the two blue prints given in the Sample Question Paper for Class X?

Ans. Based on the same design any number of the question papers can be prepared. The paper setter may generate another blue print in addition to two blue prints included in the document.

Q.26: Will the examiner cut marks if the answers are not written in serial order?

Ans.: No marks are cut. However, it is advised that the answers should be written in correct serial order as far as possible.

Q. 27: What is the procedure followed in marking the answers?

Ans.: Each answer is divided into steps and marks are given in accordance to the weightage assigned for these steps. It is advised that a copy of Marking Scheme be procured to get a clear idea.

Q. 28: In Class X Board exam. can the answers to the questions written in random order?

Ans.: Answers to the questions can be written in random order as long answers are numbered correctly. However since the answer scripts of Science and Technology will be evaluated by two examiners, answer should be written section-wise. Within the section any order may follow.

Q. 29 Does poor handwriting affect performance in the Board exams? What is the correct speed rate to follow?

Ans.: Answers should be written in a hand which can be read easily by the examiner. Being neat and legible is important. There is no speed rate prescribed. It is better to divide time and plan answers while reading the question paper in the beginning.

Q. 30: If one gets good marks in the pre-boards what does it indicate? Will the marks in the Board also be good as well?

Answer: Getting good marks in the Pre-boards clearly indicates that one has prepared well. Being consistent in preparations will definitely fetch good marks in board exams as well.

Q. 31: Is it true that longer answers in Hindi fetch better marks, as opposed to English?

Ans.: The marks are not related to the length of the answers but to the relevant value points which must be covered both in Hindi as well as in English and even in other subject

FREQUENTLY ASKED QUESTIONS (FAQ)- KVPY

2011-03-16T11:08:00.001-07:00

FREQUENTLY ASKED QUESTIONS (FAQ)

What is the syllabus for the written test?
There is no prescribed syllabus for the written test. The written test aims to test the understanding and analytical ability of the student than his/her factual knowledge. However, students are tested for the syllabus upto class XII.

I have completed my X Standard exam in 2009, am I eligible to apply for KVPY 2010?

(a) Stream SA: Students Joining in XI Std. (Science subjects) during the academic year 2010-2011 and having secured a minimum of 75% (65% for SC/ST) marks in aggregate in Mathematics and Science subjects in the X-Standard Board Examination.

(b) Stream SB: Students enrolled in the Ist Year Science undergraduate program (B.Sc./B.S./integrated M.Sc.) during the academic year 2010-2011 and having secured a minimum of 60% (50% for SC/ST) marks in aggregate in Mathematics and Science subjects in the XII Standard Board Examination.

(c) Stream SB+2 : Students enrolled in class 12 (+2) during the academic year 2010-2011 and aspiring to join undergraduate program in Basic Sciences (B.Sc./B.S./ Int. M.Sc) for the session 2011 – 2012 provided they secured a minimum of 75% (65% for SC/ST) marks in aggregate in MATHEMATICS and SCIENCE subjects in the X Standard Board Examination.

When can I be eligible for stream SP (Basic Sciences) and SP (Medicine)?

Stream SP (Basic Sciences): Students enrolled in XI/XII standard, I/II year (B.Sc./B.S./Int. M.Sc.) in Basic Sciences during the academic year 2010 – 2011 and have secured a minimum of 60% (50% for SC/ST) marks in aggregate in the X & XII Standard Board Examinations. A hard copy of an original and creative science based research project done by the applicant is required along with the application. In addition to this, students enrolled in I/II year B.E./B.Tech./B.Arch. during the academic year 2010–2011 and have secured a minimum of 60% (50% for SC/ST) marks in aggregate in X and XII Standard Board Examinations. Students enrolled in the II year B.E./B.Tech./B.Arch. program must have secured a minimum of 60% (50% for SC/ST) marks in the I year examination. A hard copy of an original and creative science based research project done by the applicant is required along with the application

Stream SP (Medicine): Students joining First/Second Professional year of M.B.B.S. program during the academic year 2009 - 2010. Students must have passed XII Standard Board Examination with 75% (65% for SC/ST) marks aggregate in Science subjects or passed First Professional MBBS exam with not less than 60% (50% for SC/ST) marks.
A hard copy of the Bio – Medical research project done by the applicant is required along with the application.

When does the KVPY advertisement come in the newspapers?
The advertisement for the KVPY Fellowship appears in all the national dailies on May 11/2010 and July 11/ 2010.

Can I avail the KVPY Fellowship along with a merit scholarship?
KVPY does not allow its Fellows to receive simultaneously fellowship/scholarship from more than one source, either government or private. In case they are in receipt of any other fellowship or scholarship they will have to relinquish it in order to avail the KVPY Fellowship.

What sort of project would be preferred (a working model or theoretical study?)

Is there a word limit for the project report?

Is it compulsory to have a blue print of some proposal which has not been tried before?

Should the project strictly deal with a theme or a topic?

Answers to 6, 7, 8 and 9:
We look for evidence of originality and innovativeness in the project. It should be precise, demonstrable if it is an experiment. It should have a new idea or a new concept, if it is a theoretical study. Routine improvement of an existing idea is generally discouraged.

ABOUT KVPY

2011-03-16T11:06:00.000-07:00

The "Kishore Vaigyanik Protsahan Yojana" (KVPY) is a program started in 1999 by the Department of Science and Technology, Government of India to encourage students of Basic Sciences, Engineering and Medicine to take up research careers in these areas. The aim of the program is to identify and encourage talented students with aptitude for research.

This program strives to assist the students to realise their potential and to ensure that the best scientific talent is developed for research and growth in the country. Generous scholarship and contingency grant are provided (up to the pre-Ph.D. level) to the selected students. In addition, summer programs for the KVPY Fellows are organized in prestigious research and educational institutions in the country.

The KVPY is funded by the Department of Science and Technology (DST), Government of India. The program is administered by the Indian Institute of Science (IISc, Bangalore). The selection of students from those studying in +1, +2, any U.G. Program in Science / Medicine and also Engineering students having aptitude for scientific research, are carried out by IISc (Bangalore), IIT-Bombay (Mumbai), and ICMR (New Delhi), respectively, in association with two Zonal Centers one at Kolkata (Indian Institute of Science Education & Research, Kolkata) and another at Mumbai (HBCSE, TIFR). There are special groups or committees set up at IISc, which screen the applications, conduct interviews at various centers, make the final selection.

The Department of Science and Technology - the nodal agency of the Government has entrusted the overall responsibility for organizing the scheme to the Indian Institute of Science, Bangalore and set up a National Advisory Committee (NAC) for overseeing its implementation. A Basic Committee and a National Scientific Committee look after both the administrative and academic aspects of the KVPY Program.

Schedule of JEE-2011

2011-03-16T10:59:00.001-07:00

The examination will be held on Sunday, April 10, 2011 as per the schedule given below:

Paper 1 9:00 to 12:00 hrs. (IST)
Paper 2 14:00 to 17:00 hrs. (IST)

The schedule will remain unaltered even if the above date is declared a public holiday

Type of Examination

There will be two question papers, each of three hours duration. Both the question papers will consist of three separate sections on Chemistry, Physics and Mathematics. They will be of objective type, designed to test comprehension, reasoning and analytical ability of candidates.
The answers for each of the questions are to be recorded on a separate, specially designed, machine-gradable sheet of paper (ORS – Optical Response Sheet). While answering each of the questions the candidate is expected to darken the bubble(s) against correct answer(s) using hard black (HB) pencils only. In some sections, incorrect answers may be awarded negative marks.
The detailed syllabi based on which JEE-2011 will be conducted, for the three subjects, namely, Chemistry, Physics and Mathematics.

IIT JEE - Chemistry Syllabus

2011-03-16T10:58:00.000-07:00

Physical chemistry

General topics: Concept of atoms and molecules; Dalton’s atomic theory; Mole concept; Chemical formulae; Balanced chemical equations; Calculations (based on mole concept) involving common oxidation-reduction, neutralisation, and displacement reactions; Concentration in terms of mole fraction, molarity, molality and normality.

Gaseous and liquid states: Absolute scale of temperature, ideal gas equation; Deviation from ideality, van der Waals equation; Kinetic theory of gases, average, root mean square and most probable velocities and their relation with temperature; Law of partial pressures; Vapour pressure; Diffusion of gases.

Atomic structure and chemical bonding: Bohr model, spectrum of hydrogen atom, quantum numbers; Wave-particle duality, de Broglie hypothesis; Uncertainty principle; Qualitative quantum mechanical picture of hydrogen atom, shapes of s, p and d orbitals; Electronic configurations of elements (up to atomic number 36); Aufbau principle; Pauli’s exclusion principle and Hund’s rule; Orbital overlap and covalent bond; Hybridisation involving s, p and d orbitals only; Orbital energy diagrams for homonuclear diatomic species; Hydrogen bond; Polarity in molecules, dipole moment (qualitative aspects only); VSEPR model and shapes of molecules (linear, angular, triangular, square planar, pyramidal, square pyramidal, trigonal bipyramidal, tetrahedral and octahedral).

Energetics: First law of thermodynamics; Internal energy, work and heat, pressure-volume work; Enthalpy, Hess’s law; Heat of reaction, fusion and vapourization; Second law of thermodynamics; Entropy; Free energy; Criterion of spontaneity.

Chemical equilibrium: Law of mass action; Equilibrium constant, Le Chatelier’s principle (effect of concentration, temperature and pressure); Significance of ΔG and ΔG° in chemical equilibrium; Solubility product, common ion effect, pH and buffer solutions; Acids and bases (Bronsted and Lewis concepts); Hydrolysis of salts.

Electrochemistry: Electrochemical cells and cell reactions; Standard electrode potentials; Nernst equation and its relation to ΔG; Electrochemical series, emf of galvanic cells; Faraday’s laws of electrolysis; Electrolytic conductance, specific, equivalent and molar conductivity, Kohlrausch’s law; Concentration cells.

Chemical kinetics: Rates of chemical reactions; Order of reactions; Rate constant; First order reactions; Temperature dependence of rate constant (Arrhenius equation).

Solid state: Classification of solids, crystalline state, seven crystal systems (cell parameters a, b, c, α, β, γ), close packed structure of solids (cubic), packing in fcc, bcc and hcp lattices; Nearest neighbours, ionic radii, simple ionic compounds, point defects.

Solutions: Raoult’s law; Molecular weight determination from lowering of vapour pressure, elevation of boiling point and depression of freezing point.

Surface chemistry: Elementary concepts of adsorption (excluding adsorption isotherms); Colloids: types, methods of preparation and general properties; Elementary ideas of emulsions, surfactants and micelles (only definitions and examples).

Nuclear chemistry: Radioactivity: isotopes and isobars; Properties of α, β and γ rays; Kinetics of radioactive decay (decay series excluded), carbon dating; Stability of nuclei with respect to proton-neutron ratio; Brief discussion on fission and fusion reactions.

Inorganic Chemistry

Isolation/preparation and properties of the following non-metals: Boron, silicon, nitrogen, phosphorus, oxygen, sulphur and halogens; Properties of allotropes of carbon (only diamond and graphite), phosphorus and sulphur.

Preparation and properties of the following compounds: Oxides, peroxides, hydroxides, carbonates, bicarbonates, chlorides and sulphates of sodium, potassium, magnesium and calcium; Boron: diborane, boric acid and borax; Aluminium: alumina, aluminium chloride and alums; Carbon: oxides and oxyacid (carbonic acid); Silicon: silicones, silicates and silicon carbide; Nitrogen: oxides, oxyacids and ammonia; Phosphorus: oxides, oxyacids (phosphorus acid, phosphoric acid) and phosphine; Oxygen: ozone and hydrogen peroxide; Sulphur: hydrogen sulphide, oxides, sulphurous acid, sulphuric acid and sodium thiosulphate; Halogens: hydrohalic acids, oxides and oxyacids of chlorine, bleaching powder; Xenon fluorides.

Transition elements (3d series): Definition, general characteristics, oxidation states and their stabilities, colour (excluding the details of electronic transitions) and calculation of spin-only magnetic moment; Coordination compounds: nomenclature of mononuclear coordination compounds, cis-trans and ionisation isomerisms, hybridization and geometries of mononuclear coordination compounds (linear, tetrahedral, square planar and octahedral).

Preparation and properties of the following compounds: Oxides and chlorides of tin and lead; Oxides, chlorides and sulphates of Fe2+, Cu2+ and Zn2+; Potassium permanganate, potassium dichromate, silver oxide, silver nitrate, silver thiosulphate.

Ores and minerals: Commonly occurring ores and minerals of iron, copper, tin, lead, magnesium, aluminium, zinc and silver.

Extractive metallurgy: Chemical principles and reactions only (industrial details excluded); Carbon reduction method (iron and tin); Self reduction method (copper and lead); Electrolytic reduction method (magnesium and aluminium); Cyanide process (silver and gold).

Principles of qualitative analysis: Groups I to V (only Ag+, Hg2+, Cu2+, Pb2+, Bi3+, Fe3+, Cr3+, Al3+, Ca2+, Ba2+, Zn2+, Mn2+ and Mg2+); Nitrate, halides (excluding fluoride), sulphate and sulphide.

Organic Chemistry

Concepts: Hybridisation of carbon; Sigma and pi-bonds; Shapes of simple organic molecules; Structural and geometrical isomerism; Optical isomerism of compounds containing up to two asymmetric centres, (R,S and E,Z nomenclature excluded); IUPAC nomenclature of simple organic compounds (only hydrocarbons, mono-functional and bi-functional compounds); Conformations of ethane and butane (Newman projections); Resonance and hyperconjugation; Keto-enol tautomerism; Determination of empirical and molecular formulae of simple compounds (only combustion method); Hydrogen bonds: definition and their effects on physical properties of alcohols and carboxylic acids; Inductive and resonance effects on acidity and basicity of organic acids and bases; Polarity and inductive effects in alkyl halides; Reactive intermediates produced during homolytic and heterolytic bond cleavage; Formation, structure and stability of carbocations, carbanions and free radicals.

Preparation, properties and reactions of alkanes: Homologous series, physical properties of alkanes (melting points, boiling points and density); Combustion and halogenation of alkanes; Preparation of alkanes by Wurtz reaction and decarboxylation reactions.

Preparation, properties and reactions of alkenes and alkynes: Physical properties of alkenes and alkynes (boiling points, density and dipole moments); Acidity of alkynes; Acid catalysed hydration of alkenes and alkynes (excluding the stereochemistry of addition and elimination); Reactions of alkenes with KMnO4 and ozone; Reduction of alkenes and alkynes; Preparation of alkenes and alkynes by elimination reactions; Electrophilic addition reactions of alkenes with X2, HX, HOX (X=halogen) and H2O; Addition reactions of alkynes; Metal acetylides.

Reactions of benzene: Structure and aromaticity; Electrophilic substitution reactions: halogenation, nitration, sulphonation, Friedel-Crafts alkylation and acylation; Effect of o-, m- and p-directing groups in monosubstituted benzenes.

Phenols: Acidity, electrophilic substitution reactions (halogenation, nitration and sulphonation); Reimer-Tieman reaction, Kolbe reaction.

Characteristic reactions of the following (including those mentioned above): Alkyl halides: rearrangement reactions of alkyl carbocation, Grignard reactions, nucleophilic substitution reactions; Alcohols: esterification, dehydration and oxidation, reaction with sodium, phosphorus halides, ZnCl2/concentrated HCl, conversion of alcohols into aldehydes and ketones; Ethers:Preparation by Williamson’s Synthesis; Aldehydes and Ketones: oxidation, reduction, oxime and hydrazone formation; aldol condensation, Perkin reaction; Cannizzaro reaction; haloform reaction and nucleophilic addition reactions (Grignard addition); Carboxylic acids: formation of esters, acid chlorides and amides, ester hydrolysis; Amines: basicity of substituted anilines and aliphatic amines, preparation from nitro compounds, reaction with nitrous acid, azo coupling reaction of diazonium salts of aromatic amines, Sandmeyer and related reactions of diazonium salts; carbylamine reaction; Haloarenes: nucleophilic aromatic substitution in haloarenes and substituted haloarenes (excluding Benzyne mechanism and Cine substitution).

Carbohydrates: Classification; mono- and di-saccharides (glucose and sucrose); Oxidation, reduction, glycoside formation and hydrolysis of sucrose.

Amino acids and peptides: General structure (only primary structure for peptides) and physical properties.

Properties and uses of some important polymers: Natural rubber, cellulose, nylon, teflon and PVC.

Practical organic chemistry: Detection of elements (N, S, halogens); Detection and identification of the following functional groups: hydroxyl (alcoholic and phenolic), carbonyl (aldehyde and ketone), carboxyl, amino and nitro; Chemical methods of separation of mono-functional organic compounds from binary mixtures

Important Dates for IIT JEE 2011

2011-03-16T10:55:00.000-07:00

Start of On-line application process Monday November 01, 2010
Closing of On-line application process Wednesday December 15, 2010
Start of Off-line application sale Friday November 12, 2010
Close of Off-line application sale Wednesday December 15, 2010
Last date of receipt completed JEE application form Monday December 20, 2010
Joint Entrance Examination

Sunday

April 10, 2011

Declaration of Results

Wednesday

May 25, 2011

On-line filling of CHOICES open to ALL the qualified candidates

Monday to Monday

May 30-June 13, 2011

Medical examination and counseling for qualified PD
Candidates (the schedule will be announced on the IIT websites)

Wednesday to Friday

June 08-10, 2011

Counseling for SC/ST/OBC candidates

Wednesday to Friday

June 08-10, 2011

Architecture/Design Aptitude Test

Friday

June 10, 2011

Last date of receipt of filled and duly signed choice sheets

Friday

June 17, 2011

Websites release of course allocation

Monday

June 27, 2011

Fugacity

2011-03-16T10:52:00.001-07:00

n chemical thermodynamics, the fugacity (f) of a real gas is an effective pressure which replaces the true mechanical pressure in accurate chemical equilibrium calculations. It is equal to the pressure of an ideal gas which has the same chemical potential as the real gas. For example, nitrogen gas (N2) at 0°C and a pressure of 100 atm has a fugacity of 97.03 atm. This means that the chemical potential of real nitrogen at a pressure of 100 atm has the value which ideal nitrogen would have at a pressure of 97.03 atm.
Fugacities are determined experimentally or estimated for various models such as a Van der Waals gas that are closer to reality than an ideal gas. The ideal gas pressure and fugacity are related through the dimensionless fugacity coefficient .

For nitrogen at 100 atm, the fugacity coefficient is 97.03 atm / 100 atm = 0.9703. For an ideal gas, fugacity and pressure are equal so is 1.
The fugacity is closely related to the thermodynamic activity. For a gas, the activity is simply the fugacity divided by a reference pressure to give a dimensionless quantity. This reference pressure is called the standard state and normally chosen as 1 atmosphere or 1 bar, Again using nitrogen at 100 atm as an example, since the fugacity is 97.03 atm, the activity is just 97.03 with no units.
Accurate calculations of chemical equilibrium for real gases should use the fugacity rather than the pressure. The thermodynamic condition for chemical equilibrium is that the total chemical potential of reactants is equal to that of products. If the chemical potential of each gas is expressed as a function of fugacity, the equilibrium condition may be transformed into the familiar reaction quotient form (or law of mass action) except that the pressures are replaced by fugacities.
For a condensed phase (liquid or solid), the chemical potential is equal to that of the vapor in equilibrium with the condensed phase, and therefore the fugacity is equal to the fugacity of the vapor. This fugacity is approxmately equal to the vapor pressure when the vapor pressure is not too high.
The word "fugacity" is derived from the Latin for "fleetness", which is often interpreted as “the tendency to flee or escape”. The concept of fugacity was introduced by American chemist Gilbert N. Lewis.

IMPORTANT DATES about IIT JEE 2010

2010-04-13T00:00:00.000-07:00

Last date of receipt of completed JEE application form

Saturday

December 19,2009

Joint Entrance Examination

Sunday

April 11,2010

Declaration of Results

Wednesday

May 26,2010

On-line filling of CHOICES open for ALL the qualified candidates

Thursday to Wednesday

May 27 to June 09, 2010

Medical examination and counselling for qualified PD candidates (the schedule will be announced on the IIT websites)

Wednesday to Friday

June 09-11,2010

SC/ST/PD/DS Counselling
OBC

Wednesday to Thursday
Thursday to Saturday

June 09-10,2010
June 10-12,2010

Last date of receipt of filled and duly signed choice sheets

Thursday

June 17,2010

Architecture / Design Aptitude Test

Thursday

June 10,2010

Website release of course allocation

Monday

June 28,2010

IIT JEE 2010 solution paper -1 and 2

2010-04-12T12:11:00.000-07:00

download the IIT JEE paper and its solution from the link given below:
IIT JEE 2010 Chemistry Paper 1 and solution :

IIT JEE 2010 chemistry paper 2 and solution :

Ionic Equilibrium key notes

2010-04-10T12:15:00.000-07:00

ionic equilibrium in solutions
ionic equilibrium
ionic equilibrium in indicators
aqueous ionic equilibrium
example of ionic equilibrium with suitable salt
solutions of equilibrium problems
saturated solutions at equilibrium
why are saturated solutions at equilibrium
differential equations equilibrium solutions
ionic solutions
aqueous ionic solutions
solutions of ionic compounds
ionic compound solutions
properties of ionic solutions
ionic reactions in aqueous solutions
aqueous solutions and ionic equations
aqueous solutions of ionic compounds
aqueous solutions of ionic and molecular compounds
law of chemical equilibrium & equilibrium constant
equilibrium and non equilibrium reactions
what does equilibrium and equilibrium mixture mean
equilibrium example
what is equilibrium
equilibrium def
equilibrium law
equilibrium help
equilibrium
gas phase equilibrium
what is solution equilibrium
equilibrium means
equilibrium motion
equilibrium net force
what is rotational equilibrium
gas equilibrium problems
equilibrium in three dimensions
dynamic equilibrium
equilibrium out of balance
equilibrium online
what is static equilibrium
what is stable equilibrium
equilibrium le chatelier
equilibrium le chateliers
stable equilibrium
what is phase equilibrium
torque and equilibrium
different types of equilibrium
what is equilibrium potential
what is equilibrium quantity
reaching equilibrium
rate law equilibrium
what is hydrostatic equilibrium
hydrostatic equilibrium example
equilibrium of bodies
rates and equilibrium
what is equilibrium position
torques and equilibrium
adsorption equilibrium
what is consumer equilibrium
what is mechanical equilibrium
general equilibrium
what is equilibrium constant
equilibrium of particles
what is equilibrium in physics
activities for equilibrium
stability of equilibrium
equilibrium concentrations
equilibrium condition
equilibrium conditions
equilibrium constant
state+equilibrium

IIT JEE 2010 solution paper -1 and 2

2010-04-10T11:38:00.000-07:00

download the solution and details
http://pkbnurture.ning.com/forum/topics/iit-jee-2010-solution-paper-1

Analysis of chemistry pattern topic wise
Organic chemistry : 39 %
Physical chemistry : 37 %
Inorganic chemistry : 24 %

paper 1 solution
http://pkbnurture.ning.com/forum/attachment/download?id=4103815%3AUploadedFile%3A1105

paper 2 solution
http://pkbnurture.ning.com/forum/attachment/download?id=4103815%3AUploadedFile%3A1106

IIT JEE 2010 solution paper -2

2010-04-10T11:31:00.000-07:00

IIT JEE 2010 - solution 2 (Pattern 1 to 10)

http://pkbnurture.ning.com/forum/attachment/download?id=4103815%3AUploadedFile%3A1105

IIT JEE 2010 solution paper -1

2010-04-10T11:02:00.000-07:00

Topper's Choice ……………………………………………………
IIT JEE 2010 Paper 1 answer Key
S. No. Pattern 1 Pattern 2 Pattern 3 Pattern 4 Pattern 5 Pattern 6 Pattern 7 Pattern 8 Pattern 9 Pattern 10
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57

Last minutes tips for exam

2010-04-06T11:20:00.001-07:00

Dear Friends,
Few words before your Final D day..............
1. Manage your time well between the 3 subjects: Physics, Chemistry and Maths. Remember that you have to attempt all three subjects in Paper 1 and Paper 2. Each paper lasts 3 hours, with a 2 hour break in between the two papers.
2. Some questions may not carry negative marks. So read instructions carefully, and solve the questions which do not carry negative marks as they represent an easy scoring opportunity. Last year, for instance, the questions with multiple correct answers did not carry negative marks.
Last Minute Tips for IIT-JEE, in detail:
Less than a week is left for one of the most prestigious entrance exam i.e IIT JEE. Students should be ready to go for the six-hour test that you have been preparing for more than two years. Let’s look at the last minute finishing touches for the most important examination of your academic career yet. There are certain basic rules that govern the operational efficiency during this phase. All these caveats are based on the assumption that you are / have been a serious student, who has been preparing for IIT-JEE – consistently -over the last two years with the right intent. We make this amply clear because there are no quick fixes for faulty preparation. Nor is there any book of formulae that will act like a magic potion of the Asterix fame.
We provide you some tips for maximizing your final phase run-up to the actual examination & suggesting certain things which are needed to take care of while appearing the exam.
On the eve of the examination
DO NOT
Do not attempt to do any lengthy problem that involves multiple steps.
Do not study a new concept or a variant of an old problem. The last day has to be spent in skimming the material. Decide that you will not do any in-depth study on the eve of the examination.
Never open a book that you have not seen till that day.
DO
Take the last three model examination papers that you have done and go through the flow of the questions and the marking scheme applicable. Tell yourself again and again that the marking scheme in the actual examination could be different from the marking scheme mentioned in the model examinations.
On the examination day:-
DO
Last year, multiple correct answers did not carry negative marks. Students who did not attempt those questions for fear of attracting penalty missed out on easy scoring opportunity. So do read the instructions given for every type of question.
After Paper 1, the only analysis that you should do is to understand the pattern of the question paper. No other analysis is worth doing during the two-hour break from 12:00 noon to 02:00 pm.
Use the restroom before entering the examination hall. Your mind needs to be completely focused on the examination paper.
DON’T
Don’t forget that the subject cut-off will be higher this year. So do’nt hesitate to give more attention to a subject in the Paper 2 if you have not attempted that subject to your satisfaction in Paper 1.
Don’t spend more that 90 minutes on any single subject in any Paper. That would be an overkill and could actually hamper your chances with respect to subject-wise cut-offs.
Do not trade last minute tips with friends or complete strangers on the day of the examination. nothing is achieved on the last day. You are what you have prepared for the last two years.
At last, student will do well to concentrate on their strengths. Remember, everybody has strong and weak areas when it comes to academics.

Finally wishing you all the best !
Do your best and hope for the best.
- Pawan

IIT JEE 2010 Solution

2010-03-13T10:44:00.000-08:00

Will be uploaded soon

42nd international chemistry olympiad...

2010-02-07T21:23:00.000-08:00

42nd IChO Tentative Program
Date Students Mentors, Observers
July 19
Mon whole
day Arrivals, Registration
July 20
Tue morning Opening Ceremony
afternoon Excursion Lab Inspection
night Lab Safety Instruction 1st Jury Meeting
July 21
Wed whole
day Excursion Translation
July 22
Thu morning Practical Exam Excursion
afternoon
night Free Time 2nd Jury Meeting
July 23
Fri whole
day Excursion Translation
July 24
Sat morning Theoretical Exam Excursion
afternoon
night Reunion Party
July 25
Sun morning Recreation Score Marking
afternoon Excursion
night 3rd Jury Meeting
July 26
Mon morning Excursion Arbitration
afternoon
night 4th Jury Meeting
July 27
Tue morning Free Time Free Time
afternoon Closing Ceremony
night Banquet
July 28
Wed whole
day Departures

For further details please visit : http://www.icho2010.org

My new homepage

2009-09-20T06:36:00.000-07:00

please visit my new homepage (under contruction)...
http://site.google.com/site/pawanbabel

suggestions are welcome.

About IIT 2009

2009-08-06T22:57:00.000-07:00

Procedure for Preparing Merit Lists

Only those candidates who attempted both Paper 1 and Paper 2 were considered for preparing the merit lists. The marks obtained by a candidate in Chemistry, Mathematics and Physics are considered to be the sum of the marks obtained in the corresponding parts in Paper 1 and Paper 2. The sum of the marks obtained in the individual subjects in JEE will be the aggregate mark for the candidate.

Minimum Qualifying Mark for Ranking (MQMR)

The average of the marks scored by all such candidates was computed for each of the three subjects. These averages were 10.44, 10.12 and 7.81 (up to two decimals) for Chemistry, Mathematics and Physics, respectively. These are the minimum qualifying mark for ranking (MQMR) in the individual subjects. Thus, a candidate qualified for ranking without relaxed norms only when he/she scored at least 11, 11 and 8 marks in Chemistry, Mathematics and Physics, respectively.

Tie-Break

The tie-break criterion in the merit lists adopted for awarding ranks to the candidates who have scored the same aggregate marks is as follows. For each subject, the mean (i.e., the average) marks has been calculated on the basis of the marks obtained by those candidates who have scored more than or equal to MQMR in that subject. These averages are 37.68, 35.29 and 33.68 (up to two decimals) for Chemistry, Mathematics and Physics, respectively. Thus, the average is the lowest for Physics and highest for Chemistry. Among the candidates having the same aggregate marks, a candidate has been ranked higher than the rest, if he/she has scored higher marks in Physics. If there is a tie after this, then a candidate has been ranked higher than the rest, if he/she has scored higher marks in Physics. Candidates tied even after this procedure, have been given the same rank.

Common Merit List (CML)

Based on the MQMR in the individual subjects, the aggregate marks obtained by the candidates and the above tie-breaking procedure and, a common merit list (CML) was prepared, without any relaxed criteria. The CML contained 8295 candidates in all. The aggregate marks scored by the last candidate in the CML is 178 and this is the CML cut-off score (CCS).

Category Merit Lists

Next, the merit list for OBC candidates has been prepared with 10% relaxation in MQMR and CML cut-off score. Similarly, merit lists for SC, ST and PD candidates have been prepared with 50% relaxation in MQMR and CML cut-off score. The numbers of candidates appeared in OBC, SC, ST and PD merit lists are 1930, 967, 208 and 138, respectively.

Preparatory Merit Lists

To select candidates for Preparatory Course against the unfilled seats reserved for SC, ST and PD candidates, three Preparatory Merit Lists have been prepared with relaxation of 50% in MQMR and aggregate cut-off for SC, ST and PD merit lists. The number of candidates in the preparatory merit lists was at most 1.5 times the number of vacant seats in these categories.

Extended Merit Lists

Extended merit lists for GE (common), OBC, SC, ST and PD candidates were prepared with further relaxations in aggregate cut-off, but not in MQMR, for use of other institutes like IISERs, IIST, RGIPT and IIMS. The lengths of these lists are six times the lengths of corresponding main merit lists of JEE-2009.

Minimum Qualifying Mark for Ranking (MQMR) and Aggregate Cut-off

Merit List

MQMR

Aggregate Cut-off
(out of 480)

Chemistry (out of 160)

Mathematics
(out of 160)

Physics
(out of 160)

General (CML)

11

11

8

178

OBC

10

10

8

161

SC

6

6

4

89

ST

6

6

4

89

PD

6

6

4

89

Marks of the first and the last ranked candidates in JEE merit lists

Merit List

Marks of the first candidate

Marks of the last candidate

Chemistry

Mathematics

Physics

Aggregate

Chemistry

Mathematics

Physics

Aggregate

General (CML)

122

153

149

424

72

31

75

178

OBC

126

143

144

413

66

63

32

161

SC

115

100

111

326

43

41

5

89

ST

106

118

95

319

25

40

24

89

PD

115

87

87

289

20

36

33

89

Maximum and minimum marks scored in different subjects by candidates in JEE merit lists

Merit List

Chemistry

Mathematics

Physics

Maximum

Minimum

Maximum

Minimum

Maximum

Minimum

General (CML)

132

11

156

12

156

15

OBC

131

14

145

14

149

15

SC

115

7

119

6

124

4

ST

106

8

118

6

103

4

PD

115

11

115

6

110

6

Aggregate cut-off for Extended Merit Lists

Merit list

General

OBC

SC

ST

PD

Aggregate cut-off

56

62

17

16

17

Aggregate Total of Different Categories (500th for GE and 100th for OBC/SC/ST/PD)

Common Merit List

Rank

Aggregate Marks

1

424

501

302

1001

278

1501

262

2001

249

2501

239

3001

230

3501

223

4001

216

4501

211

5001

205

5501

200

6001

196

6501

191

7001

187

7501

184

8001

180

8295

178

OBC Category

Rank

Aggregate Marks

1

413

101

282

201

260

301

244

401

231

501

223

601

216

701

210

801

204

901

199

1001

194

1101

190

1201

186

1301

181

1401

177

1501

174

1601

171

1701

167

1801

164

1901

161

1930

161

SC Category

Rank

Aggregate Marks

1

326

101

170

201

146

301

132

401

121

501

112

601

105

701

99

801

95

901

91

967

89

ST Category

Rank

Aggregate Marks

1

319

101

114

201

91

208

89

PD Category

Rank

Aggregate Marks

1

289

101

108

138

89

Aggregate Total and subject-wise marks for the first and last admitted candidates

Common Merit List

Maths

Physics

Chemistry

Total

AIR

153

149

122

424

1

31

75

72

178

8295

OBC Category

Maths

Physics

Chemistry

Total

AIR

143

144

126

413

1

63

32

66

161

1930

SC Category

Maths

Physics

Chemistry

Total

AIR

100

111

115

326

1

41

5

43

89

967

ST Category

Maths

Physics

Chemistry

Total

AIR

118

95

106

319

1

40

24

25

89

208

PD Category

Maths

Physics

Chemistry

Total

AIR

87

87

115

289

1

36

33

20

89

138

SYLLABUS FOR TEST PAPERS OF JAM - 2009

2009-06-07T23:00:00.000-07:00

SYLLABUS FOR BIOTECHNOLOGY (BT) TEST PAPER

The Biotechnology (BT) test paper comprises of Biology (44% weightage), Chemistry (20% weightage), Mathematics (18% weightage) and Physics (18% weightage).

BIOLOGY (10+2+3 level)

General Biology: Taxonomy; Heredity; Genetic variation; Conservation; Principles of ecology; Evolution; Techniques in modern biology. Biochemistry and Physiology: Carbohydrates; Proteins; Lipids; Nucleic acids; Enzymes; Vitamins; Hormones; Metabolism; Photosynthesis. Nitrogen Fixation, Fertilization and Osmoregulation; Nervous system; Endocrine system; Vascular system; Immune system; Digestive system, Reproductive System. Basic Biotechnology: Tissue culture; Application of enzymes; Antigen-antibody interaction; Antibody production; Diagnostic aids. Molecular Biology: DNA; RNA; Replication; Transcription; Translation; Proteins; Lipids; Membranes; Gene transfer. Cell Biology: Cell cycle; Cytoskeletal elements; Mitochondria; Endoplasmic reticulum; chloroplast; Golgi apparatus; Signaling. Microbiology: Isolation; Cultivation; Characterization and enumeration of virus; Bacteria; Fungi; Protozoa; Pathogenic micro-organisms.

CHEMISTRY (10+2+3 level)

Atomic Structure: Bohr's theory and Schrodinger wave equation; Periodicity in properties; Chemical bonding; Properties of s, p, d and block elements; Complex formation; Coordination compounds; Chemical equilibria; Chemical thermodynamics (first and second law); Chemical kinetics (zero, first, second and third order reactions); Photochemistry; Electrochemistry; Acid-base concepts; Stereochemistry of carbon compounds; Inductive, Electromeric, conjugative effects and resonance; Chemistry of Functional Groups: hydrocarbons, alkyl halides, alcohols, aldehydes, ketones, carboxylic acids, amines and their derivatives; Aromatic hydrocarbons, halides, nitro and amino compounds, phenols, diazonium salts, carboxylic and sulphonic acids; Mechanism of organic reaction; Soaps and detergents; Synthetic polymers; Biomolecules - aminoacids, proteins, nucleic acids, lipids and carbohydrates (polysaccharides); Instrumental techniques-chromatography (TLC, HPLC), electrophoresis, UV-Vis-IR and NMR spectroscopy, mass spectrometry, etc.

MATHEMATICS (10+2 level)

Sets, Relations and Functions, Mathematical Induction, Logarithms, Complex numbers, Linear and Quadratic equations, Sequences and Series, Trignometry, Cartesian System of Rectangular Coordinates, Straight lines and Family, Circles, Conic Sections, Permutations and Combinations, Binomial Theorem, Exponential and Logarithmic Series, Mathematical Logic, Statistics, Three Dimensional Geometry, Vectors, Stocks, Shares and Debentures, Average and Partition Values, Index numbers, Matrices and Determinants, Boolean Algebra, Probability, Functions, limits and Continuity, Differentiation, Application of Derivatives, Definite and Indefinite Integrals, Differential Equations, Elementary Statics and Dynamics, Partnership, Bill of Exchange, Linear Programming, Annuities, Application of Calculus in Commerce and Economics.

PHYSICS (10+2 level)

Physical World and Measurement, Kinematics, Laws of Motion, Work, Energy and Power Electrostatics, Current electricity, Magnetic Effects of Current and Magnetism, Electromagnetic Induction and Alternating Current, Electromagnetics waves, Optics, Dual Nature of Matter and Radiations, Atomic Nucleus, Solids and Semiconductor Devices, Principles of Communication, Motion of System of Particles and Rigid Body, Gravitation, Mechanics of Solids and Fluids, Heat and Thermodynamics, Oscillations, Waves.

SYLLABUS FOR CHEMISTRY (CY) TEST PAPER

PHYSICAL CHEMISTRY

Basic Mathematical Concepts : Differential equations, vectors and matrices.

Atomic Structure: Fundamental particles. Bohr's theory of hydrogen atom; Wave-particle duality; Uncertainty principles; Schrodinger's wave equation; Quantum numbers, shapes of orbitals; Hund's rule and Pauli's exclusion principle.

Theory of Gases: Kinetic theory of gases. Maxwell-Boltzmann distribution law; Equipartition of energy.

Chemical Thermodynamics: Reversible and irreversible processes; First law and its application to ideal and nonideal gases; Thermochemistry ; Second law; Entropy and free energy, Criteria for spontaneity.

Chemical and Phase Equilibria: Law of mass action; K p , K c ,K x and K n ; Effect of temperature on K; Ionic equilibria in solutions; pH and buffer solutions; Hydrolysis; Solubility product; Phase equilibria�Phase rule and its application to one-component and two-component systems; Colligative properties.

Electrochemistry: Conductance and its applications; Transport number; Galvanic cells; EMF and Free energy; Concentration cells with and without transport; Polarography.

Chemical Kinetics : Reactions of various order, Arrhenius equation, Collision theory; Theory of absolute reaction rate; Chain reactions � Normal and branched chain reactions; Enzyme kinetics; Photophysical and photochemical processes; Catalysis.

ORGANIC CHEMISTRY

Basic Concepts in Organic Chemistry and Stereochemistry: Isomerism and nomenclature, electronic (resonance and inductive) effects. Optical isomerism in compounds containing one and two asymmetric centers, designation of absolute configuration, conformations of cyclohexanes.

Aromaticity and Huckel's rule: Mono and bicyclic aromatic hydrocarbons.

Organic Reaction Mechanism and Synthetic Applications: Methods of preparation and reactions of alkanes, alkenes, alkynes, arenes and their simple functional derivatives. Mechanism and synthetic applications of electrophilic aromatic substitution. Stereochemistry and mechanism of aliphatic nucleophilic substitution and elimination reactions. Mechanism of aldol condensation, Claisen condensation, esterification and ester hydrolysis, Cannizzaro reaction, benzoin condensation. Perkin reaction, Claisen rearrangement, Beckmann rearrangement and Wagner-Meerwein rearrangement. Synthesis of simple molecules using standard reactions of organic chemistry. Grignard reagents, acetoacetic and malonic ester chemistry.

Natural Products Chemistry: Introduction to the following classes of compounds-alkaloids, terpenes, carbohydrates, amino acids, peptides and nuclei acids.

Heterocyclic Chemistry: Monocyclic compounds with one hetero atom.

Qualitative Organic Analysis: Functional group interconversions, structural problems using chemical reactions, identification of functional groups by chemical tests.

INORGANIC CHEMISTRY

Periodic Table: Periodic classification of elements and periodicity in properties; general methods of isolation and purification of elements.

Chemical Bonding and Shapes of Compounds: Types of bonding; VSEPR theory and shapes of molecules; hybridization; dipole moment; ionic solids; structure of NaCl, CsCl, diamond and graphite; lattice energy.

Main Group Elements (s and p blocks): Chemistry with emphasis on group relationship and gradation in properties; structure of electron deficient compounds of main group elements and application of main group elements.

Transition Metals (d block): Characteristics of 3d elements; oxide, hydroxide and salts of first row metals; coordination complexes; VB and Crystal Field theoretical approaches for structure, colour and magnetic properties of metal complexes.

Analytical Chemistry: Principles of qualitative and quantitative analysis; acid-base, oxidation-reduction and precipitation reactions; use of indicators; use of organic reagents in inorganic analysis; radioactivity; nuclear reactions; applications of isotopes.

SYLLABUS FOR COMPUTER APPLICATIONS (CA) TEST PAPER

The Computer Applications (CA) test paper comprises of Mathematics, Computer awareness and Analytical ability and General awareness and they will be in the ration 4:2:1.

MATHEMATICS

Algebra: Set theory and its simple applications. Basic concepts of groups, fields and vector spaces.

Matrices: Rank of a matrix. Existence and uniqueness of solution of a system of linear equation. Eigenvalues and Eigenvectors. Inverse of a matrix by elementary transformations.

Differential Calculus: Differentiation, Partial differentiation, Taylor series and approximate calculations. Maxima and minima of functions of one and two variables.

Integral Calculus: Single and multiple integration. Definite integrals, Change of order and change of variables. Application to evaluation of area, surface and volume.

Differential Equations: First order differential equations, linear differential equations of higher order with constant coefficients.

Vector Analysis: Vector algebra, Gradient.

Numerical Analysis: Solution of non linear equations using iterative methods. Interpolation (Lagrange's formula and Newton 's formulae for equidistant points). Numerical differentiation and integration (Trapezoidal and Simpson's rules).

Probability: Basic concepts of probability theory. Binomial and Poisson distributions.

Linear Programming: Formulation and its graphical solution for two variable problems.

COMPUTER AWARENESS

Elements of computers. Number systems. Basic electronic gates. Boolean algebra. Flip-Flops. Algorithmic approach to solve problems. Fundamentals of C language.

ANALYTICAL ABILITY AND GENERAL AWARENESS

Simple questions will be asked to test the analytical ability and general awareness of candidates.

SYLLABUS FOR GEOLOGY (GG) TEST PAPER

The Planet Earth: Origin of the Solar System and the Earth; Geosphere and the composition of the Earth; Shape and size of the earth; Earth-moon system; Formation of continents and oceans; Dating rocks and age of the Earth; Energy in the earth system; Volcanism and volcanic land forms; Interior of earth; Earthquakes; Earth's magnetism and gravity, Isostasy; Elements of Plate tectonics; Orogenesis.

Geomorphology: Weathering and erosion; Transportation and deposition due to wind, ice, river, sea, and resulting landforms, Structurally controlled landforms.

Structural Geology: Concept of stratum; Contour; Outcrop patterns; Maps and cross sections; Dip and strike; Classification and origin of folds, faults, joints, foliation and lineation, unconformities; shear zones.

Palaeontology: Origin and evolution of life; Fossils; their mode of preservation and utility; Morphological characters and ages of important groups of animals; Brachiopoda, Mollusca, Trilobita, Graptolitoidea, Anthozoa, Echinodermata etc. Gondwana plant fossils; Elementary idea of verterbrate fossils in India .

Stratigraphy: Principles of stratigraphy; Classification, distribution and ages of the stratigraphic formations of India from Archaean to Recent.

Mineralogy: Symmetry and forms in common crystal classes; Physical properties of minerals; Isomorphism and polymorphism, Classification of minerals; Structure of silicates; Mineralogy of common rock-forming minerals; Mode of occurrence of minerals in rocks. Transmitted polarised light microscopy and optical properties of uniaxial and biaxial minerals.

Petrology: Definition and classification of rocks; Igneous rocks- forms of igneous bodies; Crystallization from magma; classification, association and genesis of igneous rocks; Sedimentary rocks - classification, texture and structure; size and shape of sedimentary bodies. Metamorphic rocks - classification, facies, texture and properties.

Economic Geology: Properties of common economic minerals; General processes of formation of mineral deposits; Physical characters; Mode of occurrence and distribution in India both of metallic and non-metallic mineral deposits; Coal and petroleum occurrences in India .

Applied Geology: Ground Water; Mineral exploration, elements of mining and environmental geology; Principles of engineering geology.

SYLLABUS FOR GEOPHYSICS (GP) TEST PAPER

There will be Three sections in the Geophysics (GP) test paper, namely, Geology, Mathematics and Physics, each with a weightage of 50%. A candidate has to attempt any Two sections.

The syllabus for the Geology, Mathematics and Physics Sections of the Geophysics (GP) test paper are given below:
GEOLOGY SECTION

The Planet Earth: Origin of the Solar System and the Earth; Geosphere and the composition of the earth; Shape and size of the Earth; Earth-moon system; Formation of continents and oceans; dating the rocks and age of the Earth; Energy in the earth system; Volcanism and volcanic land forms; Interior of earth; Earthquakes and seismic waves; Earth's magnetism and gravity, Isostasy; Elements of plate tectonics; Orogenesis.

Geomorphology: Weathering and erosion; transportation and deposition due to wind, ice, river, sea, and resulting landforms, Structurally controlled landforms.

Structural Geology: Concept of stratum; Contour; Outcrop patterns; Maps and cross sections; Dip and strike; classification and origin of folds, faults, joints, foliation and lineation, unconformities; shear zones.

Mineralogy: Symmetry and forms in common crystal classes; physical properties of minerals; Isomorphism and polymorphism, Classification of minerals; Structure of silicates; Mineralogy of common rock-forming minerals; Mode of occurrence of minerals in rock.

Stratigraphy: Principles of Stratigraphy, Geological Time Scale, ages of major stratigraphic units of India.

Petrology: Definition and classification of rocks; Igneous rock-forms of igneous bodies; Crystallisation from magma; classification and association of igneous rocks; Principles of Stratigraphy; Sedimentary rocks-classification, texture and structure; Metamorphic rocks-Classification, facies, texture and structure.

Economic Geology: Physical properties of common ore minerals, General processes of formation of mineral deposits; Mode of occurrence of important metallic and non-metallic deposits in India; Coal, petroleum and ground water occurrences in India.

MATHEMATICS SECTION

Sequences, Series and Differential Calculus: Sequences of real numbers, Convergent sequences and series. Mean Value Theorem, Taylor 's theorem, Maxima and Minima, functions of several variables.

Integral Calculus: Fundamental theorem of calculus, Integration, Double and Triple integrals, Surface Areas and Volumes.

Differential Equations: Linear and Non-linear ODE, existence and uniqueness (without proof), Linear Differential Equations of second order with constant coefficients.

Vector Calculus: Gradient, Divergence, Curl, Laplacian, Green's, Strokes and Gauss theorems and their Applications.

Linear Algebra: System of Linear Equations, Matrices, Rank, Determinant, Inverse, eigen-values and eigen-vectros. Dimension, Linear transformations.

Real Analysis: Open and closed sets and limit points in R and completeness in R , Uniform Continuity, Power Series, Uniform Convergence.

Probability: Probability spaces, Conditional Probability, Independence , Bayes Theorem, Univariate and Bivariate Random Variables, Moment Generating and Characteristic Functions, Binomial, Poisson and Normal distributions.

Statistics: Sampling Distributions of Sample Mean and Variance, Exact Sampling Distribution (Normal Population), Simple and Composite hypothesis, Best critical region of a Test, Neyman-Pearson theorem, Likelihood Ratio Testing and its Application to Normal population, comparison of normal populations, large sample theory of test of hypothesis, approximate test on the parameter of a binomial population, comparison of two binomial populations.

Complex Analysis: Analytical functions, Harmonic functions, Cauchy's theorem, Cauchy's Integral Formula, Taylor and Laurent Expansion, Poles and Residues.

Numerical Analysis: Difference table, symbolic operators, differences of a factorial, representation of a polynomial by factorials, Forward, backward and central difference approximation formulae. Simpson's one-third rule and the error in it, Gauss-Siedel method and method of elimination for numerical solution of a system of linear equations, iteration method and its convergence, Gradient and Newton-Raphson method and their convergence.

PHYSICS SECTION

Mechanics and General Properties of Matter: Newton 's laws of motion and applications, Kepler's laws, Gravitational Law and field, Conservative and non-conservative forces. System of particles, Centre of mass, equation of motion of the CM, conservation of linear and angular momentum, conservation of energy. Elastic and inelastic collisions. Rigid body motion, fixed axis rotations, rotation and translation, moments of Inertia and products of Inertia. Principal moments and axes. Elasticity, Hooke's law and elastic constants of isotropic solid, stress energy. Kinematics of moving fluids, equation of continuity, Euler's equation, Bernoulli's theorem, viscous fluids, surface tension and surface energy, capillarity.

Oscillations, Waves and Optics: Differential equation for simple harmonic oscillator and its general solution. Superposition of two or more simple harmonic oscillators. Lissajous figures. Damped and forced oscillators, resonance. Wave equation, traveling and standing waves in one-dimension. Energy density and energy transmission in waves. Group velocity and phase velocity. Sound waves in media. Doppler Effect. Fermat's Principle. General theory of image formation. Thick lens, thin lens and lens combinations. Interference of light, optical path retardation. Fraunhofer diffraction. Rayleigh criterion and resolving power. Diffraction gratings. Polarization: linear, circular and elliptic polarization. Double refraction and optical rotation.

Electricity and Magnetism: Coulomb's law, Gauss's law. Concept of Potential, Field and Boundary Conditions, Solution of Laplace's equation for simple cases. Conductors, capacitors, dielectrics, dielectric polarization, volume and surface charges, electrostatic energy. Magnetic susceptibility, Bar magnet, Earth's magnetic field and its elements. Biot-Savart law, Ampere's law, Lenzes law, Faraday's law of electromagnetic induction, Self and mutual inductance. Alternating currents. Simple DC and AC circuits with R, L and C components. Displacement current, Maxwell's equations and plane electromagnetic waves. Lorentz Force and motion of charged particles in electric and magnetic fields.

Kinetic theory, Thermodynamics: Elements of Kinetic theory of gases. Velocity distribution and Equipartition of energy. Specific heat of Mono-, di- and tri-atomic gases. Ideal gas, Van-der-Waals gas and equation of state. Mean free path. Laws of thermodynamics. Zeroeth law and concept of thermal equilibrium. First law of thermodynamics and its consequences. Isothermal and adiabatic processes. Reversible, irreversible and quasi-static processes. Second law of thermodynamics. Carnot cycle.

Modern Physics: Blackbody radiation, photoelectric effect, Bohr's atomic model, X-rays. Wave-particle duality, Uncertainty principle, Pauli exclusion principle, Structure of atomic nucleus, mass and binding energy. Radioactivity and its applications. Laws of radioactive decay and half life, Fission and fusion

Solid State Physics, Devices and Electronics: Crystal structure, Bravais lattices and basis. Miller indices. X-ray diffraction and Bragg's law, Origin of energy bands. Concept of holes. Intrinsic and extrinsic semiconductors. p-n junctions, transistors. Amplifier circuits with transistors.

SYLLABUS FOR MATHEMATICAL STATISTICS (MS) TEST PAPER

The Mathematical Statistics (MS) test paper comprises of Mathematics (40% weightage) and Statistics (60% weightage).

Mathematics:

Sequences and Series: Convergence of sequences of real numbers, Comparison, root and ratio tests for convergence of series of real numbers.

Differential Calculus: Limits, continuity and differentiability of functions of one and two variables. Rolle's theorem, mean value theorems, Taylor 's theorem, indeterminate forms, maxima and minima of functions of one and two variables.

Integral Calculus: Fundamental theorems of integral calculus. Double and triple integrals, applications of definite integrals, arc lengths, areas and volumes.

Matrices: Rank, inverse of a matrix. systems of linear equations. Linear transformations, eigenvalues and eigenvectors. Cayley-Hamilton theorem, symmetric, skew-symmetric and orthogonal matrices.

Differential Equations: Ordinary differential equations of the first order of the form y' = f(x,y). Linear differential equations of the second order with constant coefficients.

Statistics:

Probability: Axiomatic definition of probability and properties, conditional probability, multiplication rule. Theorem of total probability. Bayes's theorem and independence of events.

Random Variables: Probability mass function, probability density function and cumulative distribution functions, distribution of a function of a random variable. Mathematical expectation, moments and moment generating function. Chebyshev's inequality.

Standard Distributions: Binomial, negative binomial, geometric, Poisson, hypergeometric, uniform, exponential, gamma, beta and normal distributions. Poisson and normal approximations of a binomial distribution.

Joint Distributions: Joint, marginal and conditional distributions. Distribution of functions of random variables. Product moments, correlation, simple linear regression. Independence of random variables.

Sampling distributions: Chi-square, t and F distributions, and their properties.

Limit Theorems: Weak law of large numbers. Central limit theorem (i.i.d.with finite variance case only).

Estimation: Unbiasedness, consistency and efficiency of estimators, method of moments and method of maximum likelihood. Sufficiency, factorization theorem. Completeness, Rao-Blackwell and Lehmann-Scheffe theorems, uniformly minimum variance unbiased estimators. Rao-Cramer inequality. Confidence intervals for the parameters of univariate normal, two independent normal, and one parameter exponential distributions.

Testing of Hypotheses: Basic concepts, applications of Neyman-Pearson Lemma for testing simple and composite hypotheses. Likelihood ratio tests for parameters of univariate normal distribution.

SYLLABUS FOR MATHEMATICS (MA) TEST PAPER

Sequences, Series and Differential Calculus : Sequences of real numbers. Convergent sequences and series, absolute and conditional convergence. Mean value theorem. Taylor 's theorem. Maxima and minima of functions of a single variable. Functions of two and three variables. Partial derivatives, maxima and minima.

Integral Calculus : Integration, Fundamental theorem of calculus. Double and Triple, integrals, Surface areas and volumes.

Differential Equations : Ordinary differential equations of the first order of the form y'=f(x,y). Linear differential equations of second order with constant coefficients. Euler-Cauchy equation. Method of variation of parameters.

Vector Calculus : Gradient, divergence, curl and Laplacian. Green's, Stokes' and Gauss' theorems and their applications.

Algebra : Groups, subgroups and normal subgroups, Lagrange's Theorem for finite groups, group homomorphisms and basic concepts of quotient groups, rings, ideals, quotient rings and fields.

Linear Algebra : Systems of linear equations. Matrices, rank, determinant, inverse. Eigenvalues and eigenvectors. Finite Dimensional Vector Spaces over Real and Complex Numbers, Basis, Dimension, Linear Transformations.

Real Analysis : Open and closed sets, limit points, completeness of R, Uniform Continuity, Uniform convergence, Power series.

SYLLABUS FOR PHYSICS (PH) TEST PAPER

Mathematical Methods: Calculus of single and multiple variables, partial derivatives, Jacobian, imperfect and perfect differentials, Taylor expansion, Fourier series. Vector algebra, Vector Calculus, Multiple integrals, Divergence theorem, Green's theorem, Stokes' theorem. First and linear second order differential equations. Matrices and determinants, Algebra of complex numbers.

Mechanics and General Properties of Matter: Newton's laws of motion and applications, Velocity and acceleration in Cartesian, polar and cylindrical coordinate systems, uniformly rotating frame, centrifugal and Coriolis forces, Motion under a central force, Kepler's laws, Gravitational Law and field, Conservative and non-conservative forces. System of particles, Centre of mass, equation of motion of the CM, conservation of linear and angular momentum, conservation of energy, variable mass systems. Elastic and inelastic collisions. Rigid body motion, fixed axis rotations, rotation and translation, moments of Inertia and products of Inertia. Principal moments and axes. Elasticity, Hooke's law and elastic constants of isotropic solid, stress energy. Kinematics of moving fluids, equation of continuity, Euler's equation, Bernoulli's theorem, viscous fluids, surface tension and surface energy, capillarity.

Oscillations, Waves and Optics: Differential equation for simple harmonic oscillator and its general solution. Superposition of two or more simple harmonic oscillators. Lissajous figures. Damped and forced oscillators, resonance. Wave equation, traveling and standing waves in one-dimension. Energy density and energy transmission in waves. Group velocity and phase velocity. Sound waves in media. Doppler Effect. Fermat's Principle. General theory of image formation. Thick lens, thin lens and lens combinations. Interference of light, optical path retardation. Fraunhofer diffraction. Rayleigh criterion and resolving power. Diffraction gratings. Polarization: linear, circular and elliptic polarization. Double refraction and optical rotation.

Electricity and Magnetism: Coulomb's law, Gauss's law. Electric field and potential. Electrostatic boundary conditions, Solution of Laplace's equation for simple cases. Conductors, capacitors, dielectrics, dielectric polarization, volume and surface charges, electrostatic energy. Biot-Savart law, Ampere's law, Faraday's law of electromagnetic induction, Self and mutual inductance. Alternating currents. Simple DC and AC circuits with R, L and C components. Displacement current, Maxwell's equations and plane electromagnetic waves, Poynting's theorem, reflection and refraction at a dielectric interface, transmission and reflection coefficients (normal incidence only). Lorentz Force and motion of charged particles in electric and magnetic fields.

Kinetic theory, Thermodynamics: Elements of Kinetic theory of gases. Velocity distribution and Equipartition of energy. Specific heat of Mono-, di- and tri-atomic gases. Ideal gas, van-der-Waals gas and equation of state. Mean free path. Laws of thermodynamics. Zeroeth law and concept of thermal equilibrium. First law and its consequences. Isothermal and adiabatic processes. Reversible, irreversible and quasi-static processes. Second law and entropy. Carnot cycle. Maxwell's thermodynamic relations and simple applications. Thermodynamic potentials and their applications. Phase transitions and Clausius-Clapeyron equation.

Modern Physics: Inertial frames and Galilean invariance. Postulates of special relativity. Lorentz transformations. Length contraction, time dilation. Relativistic velocity addition theorem, mass energy equivalence. Blackbody radiation, photoelectric effect, Compton effect, Bohr's atomic model, X-rays. Wave-particle duality, Uncertainty principle, Schrödinger equation and its solution for one, two and three dimensional boxes. Reflection and transmission at a step potential, tunneling through a barrier. Pauli exclusion principle. Distinguishable and indistinguishable particles. Max-well-Boltzmann, Fermi-Dirac and Bose-Einstein statistics. Structure of atomic nucleus, mass and binding energy. Radioactivity and its applications. Laws of radioactive decay. Fission and fusion.

Solid State Physics, Devices and Electronics: Crystal structure, Bravais lattices and basis. Miller indices. X-ray diffraction and Bragg's law, Einstein and Debye theory of specific heat. Free electron theory of metals. Fermi energy and density of states. Origin of energy bands. Concept of holes and effective mass. Elementary ideas about dia-, para- and ferromagnetism, Langevin's theory of paramagnetism, Curie's law. Intrinsic and extrinsic semiconductors. Fermi level. p-n junctions, transistors. Transistor circuits in CB, CE, CC modes. Amplifier circuits with transistors. Operational amplifiers. OR, AND, NOR and NAND gates.

Chemistry Olympiad Info

2009-05-25T01:38:00.000-07:00

Chemistry
Stages
Stage I: National Standard Examination in Chemistry (NSEC)
Eligibility:
Syllabus:
Question Paper:
Qualifying for the Second Stage:
The International Chemistry Olympiad (IChO) has been conducted since 1968, and is a competition for
students at the secondary and higher secondary school levels. The IChO helps develop friendly relations
between the young people from different countries, and thus encourages co-operation and international
understanding. India started participating in this event from the year 1999 at the 31st IChO held at Bangkok,
Thailand. India hosted the 33rd International Chemistry Olympiad (IChO) in its third year of participation in
2001 with the whole-hearted support of all countries.
To know the five stage process of this program click on .
The chemistry Olympiad program follows the following 5 stages:
Stage I: National Standard Examination in Chemistry (NSEC),
Stage II: Indian National Chemistry Olympiad (INChO),
Stage III: Orientation cum Selection Camp (OCSC) in chemistry,
Stage IV: Pre-departure Training Camp (PDT) for IChO,
Stage V: Participation in International Chemistry Olympiad (IChO).
Stage 1 is entirely the responsibility of IAPT. All the remaining stages are organized by the HBCSE.
The detailed information about eligibility and structure of the stages is given below:
NSEC is the first stage of selection of students in the chemistry Olympiad Programme which is organised by
the Indian Association of Physics Teachers (IAPT). Every student aspiring to go through successive stages of
the programme must for NSEC. NSEC will be held at a large number of in the country.
Date and Time of NSEC 2008: 23 November2008 (Sunday) 12:30 pm to 02:30 pm
Last Date forEnrollment forNSEC: 15th September 2008
All Indian students of Class XI or Class XII (Science stream) and born after December 31, 1989 are eligible to
appear for NSEC. Astudent may appear for more than one subject provided the examination schedule allows it.
See information about the examination schedule under various subjects. Students who have passed Class XII
are not eligible to enroll for NSEC 2008.
It is the student's responsibility to ensure that the eligibility criteria are satisfied. In case at any stage of the
program it is found that the student does not satisfy the eligibility criteria, he/she may be disqualified from the
program.
The syllabus for NSEC is broadly equivalent to the senior secondary level (Class XI and Class XII) of CBSE
Chemistry. This is only a rough guideline, and there is no detailed syllabus given for NSEC.
NSEC emphasizes comprehension of the subject, not rote memory. Its format will be as follows:
The question paper will consist of 80 multiple choice questions, each with only one of the four options correct
(negative marks for incorrect answers). Total marks 240.
Language : English.
Based on performance in NSEC, the top 300 students in order of merit will qualify to appear for the Second
Stage of the Olympiad program (INChO). In case there is a tie at the last position, all additional students with
the same marks will also qualify for INChO 2009.
All students who qualify to appear for INChO 2009, will get a certificate of merit from IAPT.
Stages
enroll centres
Physics-Olympiads
Stage IV: Pre-departure Training (PDT) Camp for IChO
Stage V: Participation in International Chemistry Olympiad (IChO)
The selected 4 member Indian team undergoes a rigorous training programme at HBCSE in theory and
experiment. Special laboratories have been developed at HBCSE for the purpose. Resource persons from
HBCSE and different institutions across the country are invited to train the students. The duration of training
will be subject to IChO regulations.
The 4 member student team, 2 teacher leaders and 1 scientific observer constitute the delegation to represent
India at the International Chemistry Olympiad (IChO). The 41st IChO is to be held in London, UK
tentatively in July 2009.

Syllabus for International Chemistry Olympiad (IChO)
Syllabus for Theoretical Component of IChO ---
Syllabus for the Experimental Component of IChO ---
Please note:
·The syllabus for National Standard Examination in Chemistry (NSEC) is broadly equivalent to the
senior secondary level (Class XI and Class XII) of CBSE Chemistry. This is only a rough guideline,
and there is no detailed syllabus given for NSEC.
·The syllabus for Indian National Chemistry Olympiad (INChO) is broadly similar to NSEC but the
difficulty level of the questions will be higher. Questions and problems in National Olympiads are
usually non-conventional and of high difficulty level, comparable to International Olympiads
http://www.icho.sk/Icho_Syllabus_C_(2004).pdf
http://www.icho.sk/Append_d.doc
Sample Papers for INChO
INChO 2008
Published Books
1. INChO Theory Papers (2002 - 2007) by Dr. Savita Ladage and Ms. Swapna Narvekar
This book can be purchased from
In-Charge,
HBCSE Publications Section,
Homi Bhabha Centre for Science Education,
Tata Institute of Fundamental Research,
V. N. Purav Marg, Mankhurd,
Mumbai - 400088. India
Price: Rs. 150/- (for cash purchases made in person at HBCSE)
This book can also be purchased by sending a Demand Draft of Rs. 190/- (which includes postage charges
for registered parcel) in favour of Homi Bhabha Centre for Science Education, payable at Mumbai and sent
to the address above.
REFERENCE BOOKS FOR INCHO EXAMINATION
REFERENCE BOOKS FOR PRACTICAL CHEMISTRY
Suggested references that will be useful in preparing for the theory examinations of the Indian National
Chemistry Olympiad are given here. These books are usually available in most college libraries. You may
also consult your teachers for further guidance and choice of books.
a) Physical Chemistry
Maron & Prutton, Principles of Physical Chemistry, 4th Edition, Oxford and IBH Pub. Co. Pvt. Ltd.,
New Delhi/Calcutta.
Atkins P.W., Physical Chemistry, 5th Edition, Oxford University Press.
b) Organic Chemistry
Morrison & Boyd, Organic Chemistry, 6th Edition, Prentice Hall of India Pvt. Ltd., New Delhi.
Carey, Organic Chemistry, 3rd Edition, The McGraw-Hill Companies, Inc.
Atkins & Carey, Organic Chemistry- a brief course, 2nd Edition, The McGraw-Hill Companies,
Inc.
c) Inorganic Chemistry
Lee, Concise Inorganic Chemistry, 5th Edition, ELBS with Chapman & Hall.
Cotton, Wilkinson & Gaus, Basic Inorganic Chemistry, 3rd Edition, John Wiley & Sons.
d) Analytical Chemistry
Christian, Analytical Chemistry, 5th Edition, John Wiley & Sons, Inc.
Skoog & West, Fundamentals of Analytical Chemistry, 2nd Edition, Holt International Edition.
Skoog, Principles of Instrumental Analysis, 3rd Edition, Holt-Saunders International Edition.
e) Biochemistry
Lehninger, Principles of Biochemistry , CBS publishers and distributors Pvt. Ltd., Delhi (chapters
on amino acids, proteins, carbohydrates, and lipids)
Mckee & Mckee, Biochemistry an Introduction, 2nd Edition, WCB/McGraw-Hill.
f) General Chemistry
Mahan, University Chemistry, 3rd Edition, Narosa Publishing House.
Ebbing, General Chemistry, 3rd Edition, Houghton Mifflin Company, Boston.
Schaum series books on problems in various disciplines of chemistry.
Jeffrey, Bassett, Mendham & Denney, Vogel's Textbook of Quantitative Chemical Analysis, 5th Edition,
ELBS with Longman.
Arthur I.Vogel, Elementary Practical Organic Chemistry (Part 1, 2 and 3), CBS Publishers and
Distributors, Delhi.
Addison Ault, Techniques and Experiments for Organic Chemistry, 6th Edition, University Science Books,
Sausalito, California.
Day & Underwood, Quantitative Analysis, 5th Edition, Prentice Hall of India Pvt. Ltd., New Delhi.
CBSE practical books

ConcepTest on Enthalpy:

2009-05-14T12:21:00.000-07:00

This is a series of ConcepTest questions on enthalpy, heat transfers, heat of reaction. It is best to
present them (or at least a section of them) in sequence.
Enthalpy, H, is often referred to as “heat content”.
If an object feels hot, it means...
1. it has a large enthalpy.
2. it has a low enthalpy.
3. Whether the object feels hot or not is unrelated to its enthalpy.
4. I don’t know.
Correct Answer: 3. Whether the object feels hot is unrelated to its enthalpy.
Comment to Instructor: Students tend to think that a high heat content must mean the object is hot.
They are confusing heat with temperature. Explain to the students that enthalpy is the potential to give
off heat. It does not mean the object is hot. Then go on to the next question.

∆H is defined as Hfinal − Hinitial.
If an object feels hot, it means it is undergoing a change with a ∆H that is...
1. positive.
2. negative.
Whether the object feels hot or not is unrelated to its ∆H.
3.
4. I don’t know.
Correct Answer: #2. negative.
Comment to Instructor: Students who choose #1 are probably thinking that if the object feels hot, it
must be absorbing heat, and so Hfinal would be larger than Hinitial.
Explain to the students that if the object feels hot, it is giving off heat, and so its enthalpy will become
smaller in the process. Thus Hfinal would be less than Hinitial, and ∆H would be negative. Then go on to
the next question.

If the object feels hot, it means it is undergoing...
1. an endothermic change.
2. an exothermic change.
3. Whether it feels hot or not is unrelated to whether it is undergoing endo- or exothermic
change.
Correct Answer: #2
Comment to Instructor: Some students may select #3 thinking that there is no change involved.
Clarify that change does not necessarily mean a chemical reaction. It can be simply a transfer of heat
from the object, such as a hot cup of coffee cooling down. Then explain that if it is giving off heat, it is
an exothermic change (#2.)

chemistry IIT JEE -2009 Analsyis

2009-04-24T10:19:00.000-07:00

Maximum Marks = 160
Percentage (%)
Topic Marks
Inorganic Chemistry 37
58
Organic Chemistry 34
55
Physical Chemistry 29
47

Chemistry
2009
P-1 P-2
Topic
MM 80 80
Percentage (%) Percentage (%)
Physical Chemistry 16 20 31 38.75
Atomic Structure
Chemical Equilibrium
8.75
Chemical Kinetics & Radioactivity 7
5
Electrochemistry 4
3.75 5
Gaseous State 3 4
5
Ionic Equilibrium 4
5
Solid State 4
3.75
Solution & Colligative Peroperties 3
3.75 5
Stoichiometry (Mole-1, 2) 3 4
3.75
Surface Chemistry 3
10
Thermodynamics 8
Inorganic Chemistry 31 38.75 27 33.75
10 5
Chemical Bonding 8 4
5
Coordination Compounds 4
3.75
d-Block Elements & Compounds 3
Metallurgy
3.75 25
p-Block Elements & Compounds 3 20
Periodic Table & Periodicity in Properties
15
Qualitative Analysis 12
5
s-Block Elements & Compounds 4
Organic Chemistry 33 41.25 22 27.5
Alkane, Alkyl halide-GR - -
Alkenes & Alkynes
Aromatic Compound
5
Bio chemistry 4
15
Carbonyl Compounds 12
Carboxylic Acid and Derivatives
8.75 5
General Organic Chemistry-I 7 4
3.75 3.75
General Organic Chemistry-II 3 3
Partical Organic Chemistry
13.75 13.75
Reaction Mechanism 11 11

Resonance

2009-04-24T10:06:00.000-07:00

Resonance refers to structures that are not easily represented by a single electron dot structure but that are intermediates between two or more drawn structures.

Resonance is easily misunderstood in part because of the way certain chemistry textbooks attempt to explain the concept. In science, analogies can provide an aid to understanding, but analogies should not be taken too literally. It is sometimes best to use analogies to introduce a topic, but then explain the differences and inevitable complications as further details on a complicated subject. This is the case for resonance.

Just as entropic principles cannot be applied to individual molecules, so it is impossible to say whether or not any given individual molecule with a resonance structure is literally in one configuration or another. The actual situation on the molecular scale is that each configuration of the molecule contributes a percentage to the possible configurations, resulting in a "blend" of the possible structures. Changes in molecular shape occur so rapidly, and on such a tiny scale, that the actual physical locations of individual electrons cannot be precisely known (due to Heisenberg's Uncertainty Principle). The result of all that complexity is simply this: molecules with resonance structures are treated as mixtures of their multiple forms, with a greater percentage of probability given to the most stable configurations.

The nuclei of the atoms are not moving when they are represented by resonance structure drawings. Rather, the electrons are portrayed as if they were moving instead. The true situation is that no one can say for certain exactly where any individual electron is at any specific moment, but rather electron location can be expressed as a probability only. What a dot structure is actually showing is where electrons almost certainly are located, therefore resonance structures indicate a split in those same probabilities. Chemists are absolutely certain where electrons are located when one carbon bonds four hydrogens (methane), but it is less certain where precisely any given electron is located when six carbons bond six hydrogens in a ring structrue (benzene). Resonance is an expression of this uncertainty, and is therefore the average of probable locations.

Resonance structures are stabilizing in molecules because they allow electrons to lengthen their wavelengths and thereby lower their energy. This is the reason that benzene (C6H6) has a lower heat of formation than organic chemists would predict, not accounting for resonance. Other aromatic molecules have a similar stability, which leads to an overall entropic preference for aromaticity (a subject that will be covered fully in a later chapter). Resonance stability plays a major role in organic chemistry due to resonant molecules' lower energy of formation, so students of organic chemistry should understand this effect and practice spotting molecules stabilized by resonant forms.

Carbonate
In the Lewis structures above, carbonate (CO3) has a resonance structure. Using laboratory procedures to measure the bond length of each bond, we do not find that one bond is shorter than the two others (remember, double bonds are shorter than single bonds), but instead that all bonds are of the same length somewhere between the length of typical double and single bonds.

[edit] Resonance Structures
Scheme 1. Resonance structures of Benzene

Resonance structures are diagrammatic tools used predominately in organic chemistry to symbolize resonant bonds between atoms in molecules. The electron density of these bonds is spread over the molecule, also known as the delocalization of electrons. Resonance contributors for the same molecule all have the same chemical formula and same sigma framework, but the pi electrons will be distributed differently among the atoms. Because Lewis dot diagrams often cannot represent the true electronic structure of a molecule, resonance structures are often employed to approximate the true electronic structure. Resonance structures of the same molecule are connected with a double-headed arrow. While organic chemists use resonance structures frequently, they are used in inorganic structures, with nitrate as an example.

[edit] Key characteristics

The key elements of resonance are:

* Resonance occurs because of the overlap of orbitals. Double bonds are made up of pi bonds, formed from the overlap of 2p orbitals. The electrons in these pi orbitals will be spread over more than two atoms, and hence are delocalized.
* Both paired and unshared electrons may be delocalized, but all the electrons must be conjugated in a pi system.
* If the orbitals do not overlap (such as in orthogonal orbitals) the structures are not true resonance structures and do not mix.
* Molecules or species with resonance structures are generally considered to be more stable than those without them. The delocalization of the electrons lowers the orbital energies, imparting this stability. The resonance in benzene gives rise to the property of aromaticity. The gain in stability is called the resonance energy.
* All resonance structures for the same molecule must have the same sigma framework (sigma bonds form from the "head on" overlap of hybridized orbitals). Furthermore, they must be correct Lewis structures with the same number of electrons (and consequent charge) as well as the same number of unpaired electrons. Resonance structures with arbitrary separation of charge are unimportant, as are those with fewer covalent bonds. These unimportant resonance structures only contribute minimally (or not at all) to the overall bonding description; however, they are important in some cases such as for a carbonyl group.
* The hybrid structure is defined as the superposition of the resonance structures. A benzene ring is often shown with a circle inside a hexagon (in American texts) rather than alternating double bonds — the latter example misrepresents the electronic structure. Bonds with broken bond orders are often displayed as double bonds with one solid and one dashed line.

[edit] What resonance is not

Significantly, resonance structures do not represent different, isolatable structures or compounds. In the case of benzene, for example, there are two important resonance structures - which can be thought of as cyclohexa-1,3,5-trienes. There are other resonance forms possible, but because they are higher in energy than the triene structures (due to charge separation or other effects) they are less important and contribute less to the "real" electronic structure (average hybrid). However, this does not mean there are two different, interconvertable forms of benzene; rather, the true electronic structure of benzene is an average of the two structures. The six carbon-carbon bond lengths are identical when measured, which would be invalid for the cyclic triene. Resonance should also not be confused with a chemical equilibrium or tautomerism which are equilibria between compounds that have different sigma bonding patterns. Hyperconjugation is a special case of resonance.

[edit] History

The concept of resonance was introduced by Linus Pauling in 1928. He was inspired by the quantum mechanical treatment of the H2+ ion in which an electron is located between two hydrogen nuclei. The alternative term mesomerism popular in German and French publications with the same meaning was introduced by Christopher Ingold in 1938 but did not catch on in the English literature. The current concept of Mesomeric effect has taken on a related but different meaning. The double headed arrow was introduced by the German chemist Arndt (also responsible for the Arndt-Eistert synthesis) who preferred the German phrase zwischenstufe or intermediate phase.

Due to confusion with the physical meaning of the word resonance, as no elements do actually appear to be resonating, it is suggested to abandon the term resonance in favor of delocalization [1]. Resonance energy would become delocalization energy and a resonance structure becomes contributing structure. The double headed arrows would get replaced by commas.

[edit] Examples
Scheme 2. Examples of resonance ozone, benzene and the allyl cation

The ozone molecule is represented by two resonance structures in the top of scheme 2. In reality the two terminal oxygen atoms are equivalent and the hybrid structure is drawn on the right with a charge of -1/2 on both oxygen atoms and partial double bonds. The concept of benzene as a hybrid of two conventional structures (middle scheme 2) was a major breakthrough in chemistry made by Kekule, and the two forms of the ring which together represent the total resonance of the system are called Kekule structures. In the hybrid structure on the right the circle replaces three double bonds. The allyl cation (bottom scheme 2) has two resonance forms and in the hybrid structure the positive charge is delocalized over the terminal methylene groups.
In chemistry delocalized electrons are electrons in a molecule that are not associated with a single atom or to a covalent bond. Delocalized electrons are contained within an orbital that extends over several adjacent atoms. Classically, delocalized electrons can be found in conjugated systems of double bonds and in aromatic and mesoionic systems. A case of delocalized electrons occurs also in solid metals, where the d-subshell interferes with the above s-subshell, and contributes to the properties of a metal. It is increasingly appreciated that electrons in sigma bonding levels are also delocalized. For example, in methane, the bonding electrons are shared by all five atoms equally. Pervasive existence of delocalization is implicit in Molecular Orbital Theory.

In the simple aromatic ring of benzene the delocalization of six π electrons over the C6 ring is often graphically indicated by a circle. The fact that the six C-C bonds are equidistant is one indication of this delocalization. In Valence Bond Theory, delocalization in benzene is represented by resonance structures.

Another example of delocalized electrons can be found in a carboxylate group, wherein the negative charge is centered equally on the two oxygen atoms.

Delocalized electrons are important for several reasons. One, an expected chemical reaction may not occur because the electrons delocalize to a more stable configuration, resulting in a reaction that happens at a different location. An example attempting the Fridel-Crafts alkylation of benzene with 1-chloro-2-methylpropane; the carbocation rearranges to a tert-butyl group stabilized by hyperconjugation, a particular form of delocalization.

Delocalized electrons also exist in the structure of metals. Metallic structure consist of aligned positive ions (cations) in a "sea" of delocalized electrons. This means that the electrons are free to move throughout the structure, and gives rise to properties such as conductivity.

In diamond all four outer electrons of each carbon atom are 'localized' between the atoms in covalent bonding. The movement of electrons is restricted and diamond does not conduct an electric current. In graphite, each carbon atom uses only 3 of its 4 outer energy level electrons in covalently bonding to three other carbon atoms in a plane. Each carbon atom contributes one electron to a delocalized system of electrons that is also a part of the chemical bonding. The delocalized electrons are free to move throughout the plane. For this reason, graphite conducts electricity along the planes of carbon atoms, but does not conduct in a direction at right angles to the plane.

A conjugated system occurs in an organic compound where atoms covalently bond with alternating single and multiple (e.g. double) bonds (e.g., C=C-C=C-C) and influence each other to produce a region called electron delocalization. In this region electrons do not belong to a single bond or atom, but rather a group. For example, phenol (C6H5OH, benzene with hydroxyl group) (diagramatically has alternating single and double bonds), which has a system of 6 electrons above and below the flat planar ring, as well as around the hydroxyl group.

The conjugated system results in a general delocalization of the electrons across all of the adjacent parallel aligned p-orbitals of the atoms, which increases stability and thereby lowers the overall energy of the molecule [1].

Conjugation can be maintained by the presence of different kinds of p-orbital-donating groups. Furan is considered a conjugated system for this reason.

Conjugation is possible by means other than the presence of alternating single and double bonds. As long as each contiguous atom in a chain possesses a p-orbital, the system can be considered conjugated. For example, furan (shown at right) is a five-membered ring with two alternating double bonds and an oxygen in position 1. Oxygen has two lone pairs, one of which occupies a p-orbital on that position, thereby maintaining the conjugation of that five-membered ring. The presence of a nitrogen in the ring or groups α to the ring like a carbonyl group (C=O), an imine group (C=N), a vinyl group (C=C), or an anion will also suffice as a source of pi orbitals to maintain conjugation.

Conjugated systems have unique properties that give rise to strong colors. Many pigments make use of conjugated electron systems, such as beta-carotene's long conjugated hydrocarbon chain resulting in a strong orange color. When an electron in the system absorbs a photon of light of the right wavelength, it can be promoted to a higher energy level. (See particle in a box). Most of these electronic transitions are of a p-orbital electron to a p-antibonding orbital (π to π*), but non-bonding electrons can also be promoted (n to π*). Conjugated systems of fewer than eight conjugated double bonds absorb only in the ultraviolet region and are colorless to the human eye. With every double bond added, the system absorbs photons of longer wavelength (and lower energy), and the compound ranges from yellow to red in color. Compounds that are blue or green typically do not rely on conjugated double bonds alone.

This absorption of light in the ultraviolet to visible spectrum can be quantified using UV/VIS spectroscopy, and forms the basis for the entire field of photochemistry.
Chemical structure of beta-carotene. The eleven conjugated double bonds that form the chromophore of the molecule are highlighted in red.

Conjugated systems form the basis of chromophores, which are light-absorbing parts of a molecule which can cause a compound to be colored. Such chromophores are often present in various organic compounds and sometimes present in polymers, which are colored or glow in the dark. They are usually caused by conjugated ring systems with bonds such as C=O and N=N in addition to conjugated C-C bonds.
The native conformation of cyclooctatetraene. Adjacent double bonds are not coplanar, so there is not strong conjugation between them.

Conjugation in cyclic structures results in aromaticity, an unusual stability found in cyclic conjugated systems.

It is important to note that merely possessing alternating double and single bonds is not enough for a system to be strongly conjugated. Some cyclic hydrocarbons (such as cyclooctatetraene) do indeed possess alternating single and double bonds. Although the molecule may appear planar if one looks only at its chemical structure, it is in fact not, and typically adopts a "tub" conformation. Because the p-orbitals of the molecule do not align themselves well in this non-planar molecule, the electrons are not as easily shared between the carbon atoms. They can be still considered conjugated, but they are not considered antiaromatic (and also not aromatic; see Hückel's rule). Cyclooctatetraene would not be considered antiaromatic because it is not planar.

IIT- JEE 2009 Analysis + PATTERN

2009-04-12T08:54:00.001-07:00

IIT- JEE 2009
Changing pattern of the IIT JEE is nothing new – recent years have experienced many
such changes. However, the JEE 2009 there was a qualitative shift in the kind of
questions asked – these do not require a lot of rigorous problem solving, but rather a
fairly good understanding of the concepts and the ability to comprehend and analyse.
This shift is welcome. The major changes: disappearance of assertion reasoning type of
questions, subjective questions back in paper and negative marking in one or more than
one correct choice types.
Expected Cut off
Whereas a score of about 170 can be suitable for securing name in the common merit list.
An average student has chances to score almost equally in all three sections.

Level of difficulty

SUBJECT PAPER 1 PAPER 2
Physics Easy Difficult
Chemistry Difficult Easy
Mathematics Easy Difficult
Whereas in totality maths had the highest level of difficulty followed by physics and
then chemistry.

Paper 1
Marks Negative Total Remarks
per Marks Marks
Ques.
Section 1: 3 -1 24 Multiple choice, with
8 Questions only one correct option

Section 2: 4 -1 16 Multiple choice one or more than one can
be correct
4 Questions
Section 3: 4 -1 24 Passage-based questions, 3 questions per passage
2 Pasages,
6 Questions
Section 4 8 0 16 Match the matrix type.
2 Questions

Paper 2
Marks Negative Total Remarks
per Marks Marks
Ques.
Section 1: 3 -1 12 Multiple choice, with
4 Questions only one correct option

Section 2: 4 -1 20 Multiple choice one or more than one can be correct
5 Questions

Section 3: 8 0 16 Match the matrix type
2 Questions

Section 4: 4 -1 32 Subjective type
8 Questions

IIT JEE 2009 Solution -Chemistry paper1

2009-04-12T08:13:00.000-07:00

CHEMISTRY PAPER -1 IIT 2009

IIT JEE 2009 paper

2009-04-12T05:55:00.000-07:00

IIT JEE 2009 paper solution will be uploaded soon...

Olympiads

2009-04-04T08:46:00.000-07:00

Enthalpy and Thermochemical Equations?
Thermochemical equations are just like other balanced equation except they also specify the heat flow for the reaction. The heat flow is listed to the right of the equation using the symbol ΔH. The most common units are kilojoules, kJ. Here are two thermochemical equations:

H2 (g) + ½ O2 (g) → H2O (l); ΔH = -285.8 kJ

HgO (s) → Hg (l) + ½ O2 (g); ΔH = +90.7 kJ

When you write thermochemical equations, be sure to keep the following points in mind:

1. Coefficients refer to the number of moles. Thus, for the first equation, -282.8 kJ is the ΔH when 1 mol of H2O (l) is formed from 1 mol H2 (g) and ½ mol O2.
2. Enthalpy changes for a phase change, so the enthalpy of a substance depends on whether is it is a solid, liquid, or gas. Be sure to specify the phase of the reactants and products using (s), (l), or (g) and be sure to look up the correct ΔH from heat of formation tables. The symbol (aq) is used for species in water (aqueous) solution.
3. The enthalpy of a substance depends upon temperature. Ideally, you should specify the temperature at which a reaction is carried out. When you look at a table of heats formation notice that the temperature of the ΔH is given. For homework problems, and unless otherwise specified, temperature is assumed to be 25°C. In the real world, temperature may different and thermochemical calculations can be more difficult.

Certain laws or rules apply when using thermochemical equations:

1. ΔH is directly proportional to the quantity of a substance that reacts or is produced by a reaction.

Enthalpy is directly proportional to mass. Therefore, if you double the coefficients in an equation, then the value of ΔH is multiplied by two. For example:

H2 (g) + ½ O2 (g) → H2O (l); ΔH = -285.8 kJ

2 H2 (g) + O2 (g) → 2 H2O (l); ΔH = -571.6 kJ
2. ΔH for a reaction is equal in magnitude but opposite in sign to ΔH for the reverse reaction.

For example:

HgO (s) → Hg (l) + ½ O2 (g); ΔH = +90.7 kJ

Hg (l) + ½ O2 (l) → HgO (s); ΔH = -90.7 kJ

This law is commonly applied to phase changes, although it is true when you reverse any thermochemical reaction.
3. ΔH is independent of the number of steps involved.

This rule is called Hess's Law. It states that ΔH for a reaction is the same whether it occurs in one step or in a series of steps. Another way to look at it is to remember that ΔH is a state property, so it must be independent of the path of a reaction.

If Reaction (1) + Reaction (2) = Reaction (3), then ΔH3 = ΔH1 + ΔH2

Latent Heat

When a substance changes phase, that is it goes from either a solid to a liquid or liquid to gas, the energy, it requires energy to do so. The potential energy stored in the interatomics forces between molecules needs to be overcome by the kinetic energy the motion of the particles before the substance can change phase.

If we measure the temperature of the substance which is initially solid as we heat it we produce a graph like Figure(below).

Temperature change with time. Phase changes are indicated by flat regions where heat energy used to overcome attractive forces between molecules

Starting a point A, the substance is in its solid phase, heating it brings the temperature up to its melting point but the material is still a solid at point B. As it is heated further, the energy from the heat source goes into breaking the bonds holding the atoms in place. This takes place from B to C. At point C all of the solid phase has been transformed into the liquid phase. Once again, as energy is added the energy goes into the kinetic energy of the particles raising the temperature, (C to D). At point D the temperature has reached its boiling point but it is still in the liquid phase. From points D to E thermal energy is overcoming the bonds and the particles have enough kinetic energy to escape from the liquid. The substance is entering the gas phase. Beyond E, further heating under pressure can raise the temperature still further is how a pressure cooker works.

Latent Heat of Fusion and Vaporisation

The energy required to change the phase of a substance is known as a latent heat. The word latent means hidden. When the phase change is from solid to liquid we must use the latent heat of fusion, and when the phase change is from liquid to a gas, we must use the latent heat of vaporisation.

The energy require is Q= m L, where m is the mass of the substance and L is the specific latent heat of fusion or vaporisation which measures the heat energy to change 1 kg of a solid into a liquid.

Table show the Latent Heat !!!!

Olympiads
Every student in grade 12th who wants to get through IIT –JEE bears a dream: To qualify Olympiads. Olympiads in Math, Physics, Chemistry begin at regional (RMO) level and go upto International level (INO). Some websites where you can check out information, questions and other related topics are given below:

• Indian National Math Olympiad
• Indian Physics & Chemistry Olympiads
• International Physics Olympiad
• International Chemistry Olympiad
• International Science Olympiads
• International Math Olympiad (IMO)
• IMO Problems Archive
• Asian Physics Olympiad

Books for Olympiads:

• GEOMETRY

1. Durrel M. A., Modern Geometry Macmillan & Co., London.
2. H. S. M. Coxeter and S. L. Greitzer, Geometry Revisited Mathematical Association of America.
3. S. L. Loney, Plane Trigonometry Macmillan & Co., London.

• NUMBER THEORY

1. I. Niven & H. S. Zuckerman An Introduction to the Theory of Numbers Wiley Eastern Ltd. New Delhi.
2. David Burton Elementary Number Theory Universal Book Stall, New Delhi.
3. G. H. Hardy & Wright An introduction to the theory of numbers, Oxford University Publishers.

• JOURNALS

1. Samasya, journal devoted to problem solving, published by Leelavati trust, Bangalore.
2. Bona Mathematica, published by Bhaskaracharya Prathistana , Pune.

Here are some excellent books on chemistry in general:

* Molecules.
Peter W. Atkins.
Scientific American Library, Freeman Press, 1987. [See this book at Amazon.com]

* Chemistry: Principles and Applications.
Peter W. Atkins.
Longman, 1988. [See this book at Amazon.com]

* The Periodic Kingdom: A Journey into the Land of the Chemical Elements.
Peter W. Atkins.
Basic Books, 1995. [See this book at Amazon.com]

* Designing the Molecular World: Chemistry at the Frontier .
Philip Ball.
Princenton Univ Press, 1994. [See this book at Amazon.com]

* Chemical Principles, 4th Edition.
Richard E. Dickerson, H. B. Gray, M. Y. Darensbourg.
Benajamin/Cummings, 1984. [See this book at Amazon.com]

* Chemistry of the Elements.
Norman N. Greenwood and A. Earnshaw.
Pergamon, 1984. [See this book at Amazon.com]

* General Chemistry.
Linus Pauling.
Dover Books, 1989. [See this book at Amazon.com]

* Chemical Curiosities: Spectacular Experiments and Inspired Quotes.
H. W. Roesky, K. Mockel, Roald Hoffman.
Vch Pub, 1996. [See this book at Amazon.com]

The authoritative data book, which can be found in every self-respecting chemistry and physics laboratory is:

* CRC Handbook of C hemistry and Physics, 78th Edition. (table of contents)
David R. Lide (editor-in-chief) and H.P.R. Frederikse (assoc.ed.)
CRC Press, 1997. [See this book at Amazon.com]

There exist student editions of this book as well. Older editions of the CRC Handbook are also still very useful.

Free TEST PAPER for IIT JEE, AIEEE and CET

2009-04-02T10:26:00.000-07:00

Check out http://www.snapwiz.co.in, it has 10 free practice test for each AIEEE/IIT/CET and all questions have detailed answers along with video explanations.

ENDQUOTE FOR IIT-JEE

2009-03-26T20:13:00.000-07:00

Endquote For IIT-JEE

IIT-JEE is a not only an academic test but it is also a test of one's temperament as well as course planning. It is only the hardworking and intelligent student, who comes at the top. The general notion is that JEE is a difficult examination and the questions are complex and tough. This is not true. It is merely a different exam. All it requires is a proper examination temperament and different approach to the subject than most of the other exams.

Competition is really tough in IIT-JEE because of limited seats in IIT. It will be tougher for open category student to entre in IIT. Government also allotted 26% reservation for OBC category student.

There is no any shortcut for success. If you want to achieve anything in your life you have to work hard and develop yourself up to that level which is level of success.

IIT-JEE is not about to just study physics, chemistry and Mathematic it is about to develop your confidence level, your patience, develops your analytical and logical thinking. Develop your problem handling ability. Try to think higher always remember your dream and start work on it.

To have optimum success and avoid failing one has to develop excellent examination temperament besides knowledge of the subject and problem solving skills.

How To make Effective Notes

2009-03-26T20:12:00.001-07:00

Making notes is very good for revision of any subject. It will be better for you to create your own notes rather than taking your friends. When you are creating your own notes then you are clearing your concept about that topic or subject.

Here I am giving you some tips to create effective notes.

1.When you are making notes of any subject/topic first read that topic carefully and write it’s summery on paper what you have understand this method will help you to undersyand all the aontent inside the topic in better way after that start making notes. During the notes making draw the diagram at the right hand side of the paper. Important chemical reaction and formula make in a box.

2.When you are making notes rather than making notes in words make notes in histogram & tree diagram as much as possible. Making notes with the help of tree diagram will take less time for revision.

3. When you are making notes underline important word with some colour pen. This will helpful to you to remember important words.

4.When you are making notes use your own words means express your notes in your own language. It is not important to use books words makes notes such a way that it should be easily understable.

5. try as much as possible to make notes in simple language rather than using tough English when you are making notes for particular subject use more than one book atleast.

Check Application status of IIT-JEE 2009

2009-03-26T20:11:00.000-07:00

For IIT-JEE aspirants tension regarding IIT-JEE application form is quite obvious . now IIT-JEE aspirants can check their status of their application form .

To check status of IIT-JEE application form
Log on
http://www.jee.iitm.ac.in

At right hand side of the website you will get a link "Registration No. Allotment" click on it. A new window will be open submit your application form No. and trace your status of application form.

if you have posted your IIT-JEE application form with speed d post then you you can also trace detail about your post for this follow the following steps

Log on
http://indiapost.gov.in
at upper side of the website you will get a link "Speed Post" put your mouse over it a drop down menu will be open click on " Tracking"

" submit your speed post number " and get status of your post

BOOKS for IIT JEE

2009-03-18T23:22:00.000-07:00

Listed below books that will help you prepare for the D-day

Students often look hard to find the best book and study material to prepare for a subject. However, they must realise that since most of the syllabus is already covered in their syllabus of class 11 and 12 they need not wait to start studying for IIT JEE.

Start with books you already have. Make sure that you have a thorough knowledge and understanding of the concepts. Solve all the questions step-by-step and then graduate on to the other books that have been recommended for IIT JEE.

Most of the books listed here will have similar questions and topics, though there are a few which indeed have some novelty in them and are easier to understand. We will present you a list of subject-wise books for you to study:

Physics

Books that you must have
Concepts of Physics Vol. I and II by H.C. Verma is good for theory in Mechanics, Electricity & Magnetism, Optics, Modern Physics, Heat & Waves and Thermodynamics.
NCERT Physics of Class XI and XII
You may also buy

IIT Physics Guide by Gupta & Gupta
Interactive Physics by MTG is the only book of its kind in the market and covers topics like Rotational Mechanics really well.
Krishna's Guide for IIT Physics
New Pattern IIT JEE Physics by D.C. Pandey is the best book for problems of Mechanics and Thermodynamics.
Physics by Halliday, Resnick & Krane is the best one for Thermodynamics.
Physics I & II by Halliday & Resnick is good for theory of Mechanics, Electricity, Heat & Waves and Magnetism.
Problems in General Physics by I. E. Irodov is good for Modern Physics, Mechanics and Electricity & Magnetism.
Problems in Physics by Abhay Kumar Singh
Schaum's 3000 Solved Problems in Physics
Maths

Books that you must have
NCERT Books, and Maths XI and XII by R. S. Agarwal are good enough for topics of Algebra like Inequality, Probability, and Progression. However, you will need lots of solved examples along with them for practice.
Play with Graphs by Amit Agarwal is a very good book to help you understand graphs. It is very useful for both Screening and Mains.
TMH Mathematics IIT Guide is good for solved examples. However, you must buy only the latest edition for best results. Exercises are not enough but there are about 100 solved examples for each chapter that you can practice with.
Books by S. L. Loney are good for Vector, Coordinate Geometry, Trigonometry and Calculus.
Differential Calculus by Amit Agarwal and Integral Calculus by Amit Agarwal has a decent and novel collection of problems. The level of problems is also good.
You may also buy
3000 Solved Problems in Maths by Schaum Series by TMH is good for practice.
Books by Piskunov, and Shanti Narayan are good for Vector, Trigonometry and Calculus.
Differential Calculus by Edwards and Integral Calculus by Edwards
For those who find Calculus really tough, there is a very good book by Thomas and Finney, offered by Pearson Education. It has several good examples and exercises. Theory is covered in detail, along with formulas and diagrams. The CD offered with the book is really useful too.
Higher Algebra by Barnard & Child, and Hall & Knight.
Introduction to Probability & its Applications by Willliam Feller
K. D. Joshi's book that has only JEE and Olympiad problems and is good for revision purposes.
M L Khanna’s IIT Math Guide has lots of solved examples throughout the book. It is good for Calculus, Algebra, Coordinate Geometry, and Vectors.
MCQ (Multiple Choice Questions) by Bharati Bhawan Publications is good for practice too.
Problems in Calculus of One Variable by I. A. Maron
Problems in Mathematical Analysis by Berman
‘Problems Plus in IIT Maths’, written by Das Gupta, has some good problems to practice. However, if you have TMH, you won't need this one.
Chemistry

Books that you must have
IIT Chemistry Guide by O. P. Agarwal is recommended for Inorganic Chemistry and Physical Chemistry.
NCERT Chemistry for XI and XII
Physical Chemistry by P. Bahadur has a good number and level of solved examples. However, it has little theory, and exercises are not that great.
Concise Inorganic Chemistry by J. D. Lee
Organic Chemistry by Morrison & Boyd
Organic Chemistry by I L Finar Vol. I
You may also buy
Book by O. P. Tandon is good for beginners.
Inorganic Chemistry by P. L. Soni
Inorganic Chemistry by Satyaprakash, Madan, Bahl & Tuli
Introduction to Chemical Calculations by R C Mukherjee
Krishna's IIT
Numerical Chemistry by Gurtu & Kapoor
Numerical Chemistry by Sarin & Sarin
Organic Chemistry by Arihant Prakashan is very good but has several errors too.
Organic Chemistry by Bahl & Bahl
Organic Chemistry by Jerry March
Organic Chemistry by Solomons
Physical Chemistry by Castellan
Physical Chemistry by P. W. Atkins
Reaction Mechanism by Peter Skyes is very good.
Schaum's 3000 Solved Problems in Chemistry is good for practice.
Study Guide to Organic Chemistry by Morrison & Boyd
Study Guide to Organic Chemistry by Solomons
Concise IIT Chemistry by PKB
However, there is no need of being threatened by the long list suggested above. The study material provided by prestigious sources like ....... often covers all the topics in detailed and concise form and do not require additional books for reference.

So, get busy with your schoolbooks, and buy NCERT books, if you don’t already have them. You can use free study material online and buy books only if you really need help on a topic.

If you need experts’ help, you can send me email chemistryiit[a]gmail.com

Strategies for IIT JEE

2009-03-18T23:20:00.000-07:00

Here's a list of simple things you could consider to make your IIT-JEE experience easier

Start brushing up with the variety of topics to improve the numerical questions you want to attempt. Avoid lengthy questions instead the focus should be on objective questions. As these last 20 days are very crucial, concentrate on breadth rather than depth.

All the formulae should be revised so that these are on the tips and comes to you without any effort.

The test has negative marking for all three papers; therefore, the familiarity with the concept will be crucial.

The day before the exam
Take at least 6-8 hrs. of sleep so that the brain works in the best mode while you are solving the papers.
Eat light meal. Taking a heavy meal can make you drowsy.
Do not revise those topics which you have not studied earlier. Also do not start any new topic just before the exam. Try to get rid of any feeling of fear which occurs out of being your test centre in other town.
Reach the centre 30 minutes prior to the exam. If you are not aware where your centre is, visit it a day before the exam.
Do not visit the test centre empty stomach.
If you suffer any headache or nausea keep the medicine with you.
If you are planning to go to the test centre by vehicle, make sure the vehicle is in order.
Keep all the necessary documents, a digital watch and necessary equipments (pen pencil eraser etc.) with you on the big day.
Just before the exam
Keep your permission letter on the desk to show it to the exam supervisor.
Never use a red pen. Keep a black ball-point pen(not gel or ink pen) besides a pencil.
Synchronize your watch with the clock at the test centre.
Into the exam
Read all the instructions carefully
Solve those questions first about which you are fully confident.
There are some questions which are time consuming but you are confident that you can solve these questions, so keep these questions for the second round of question attempting.
There are some questions about which you think you will not be able to solve them so do not waste time over such questions.
You can indicate the difficulty level of the questions by marking them as a,b,c etc.
Do not attempt the questions in haste.
The motto should be – one question at a time.
Rough work should be done in the space given in the question paper.
Now the concept of individual cutoff has been removed , so make sure that you attempt as many questions as possible in that subject which you feel more confident.
Some questions require a diagram in order to have an understanding so do make one.
While solving the questions of numerical, if the value is not mentioned then use the one which you remember.

Last minute tips to crack IIT JEE-

2009-03-18T23:13:00.000-07:00

There are few days left for the IIT JEE 2009. Students are advised not to study new topics at this stage.

Instead, they should revise what they already know and lift up their level of confidence.

The IIT JEE is likely to be stressful. The students will take two 3-hour papers one after the other. To prepare for such situation, students must create exam like conditions and take a few mock exams and make sure that they follow the same time schedule as will be done in the JEE on April 12.

Mental preparation is a must. Students are advised to go through past years’ questions just to tell themselves that the papers in the past have not been that difficult.

Students are advised against trying to solve a whole lot of problems at this stage. They must also avoid doing complicated problems.

Relaxing, sleeping well, eating healthy, etc. are also very important.

At the exam:

Competitive exams can be full of surprises. The best way to face these is to be mentally ready for any eventuality. Please do not go with any expectations such as the number of questions, types of questions, marks, etc. Read the instructions very carefully and plan your strategy if there is any unexpected surprise.

Since each paper will contain all three subjects, students would do well to allocate their time to each subject judiciously. IIT JEE is a strange exam. No matter how bad you may think you have performed in a paper, there still may be possibility of your clearing the cutoff. Remember that your rank will be decided based on your performance in all three subjects.

During the break, avoid discussing the previous paper with friends. Also, try and relax, have very light food, and lots of fluids.

After getting the question paper, spend 10 minutes in reading through all the questions. In doing so, you may also mentally mark the questions that seem easier. The idea is to get comfortable with whatever is there in the paper.

In some questions it may be possible to arrive at the right answer from the given alternatives by substituting variables with numerical values.

Do not try to do any calculations till you have reached the last step.

If you get stuck at any stage, immediately move to another question. If you get time you may come back to the unfinished question later.

Crack Chemistry @ IIT ....

Chemistry is one of the most important and scoring section of JEE. One of the most important feature of chemistry as a subject in JEE exam is the homogeneity of the paper
You will find at least one question from almost all chapters three sub division of chemistry ,viz., Physical, organic and inorganic chemistry has almost equal weightage , the first two having slight advantage over the third.

The following is expected to be the marks-wise breakup for topics based on previous year’s papers:
TOPICS PERCENTAGE (MARKS)
General Chemistry 8%
Physical chemistry 30%
Organic Chemistry 35%
Inorganic Chemistry 27%

1. While all topics are important, based on analysis of past years’ papers, following sub-topics have a higher probability of figuring in the paper:
TOPICS SUB TOPICS PROBABILITY
Atomic Structure Heisenberg principle, Quantum numbers High
Chemical Bonding Hybridisation, Dipole moment, MOT High*
Chemical Energetics Resonance energy, First law of thermodynamics High
Ionic Equilibrium Salt hydrolysis, Buffers and Solubility product High
Chemical Kinetics Arrhenius equation High
Electrochemistry Electrolysis and conductance, Concentration cell High
Gaseous And Liquid State Kinetic gas theory, Diffusion High
General Organic Chemistry All topics High
Hydrocarbons Alkanes, Alkynes, Markovnikov’s rules High *
Ethers Breaking of ether linkage High *
Aldehydes & Ketones Aldol condensation, Nucleophilic addition High
Carboxylic Acid & Its Functional Derivatives Carboxylic acid, High
Amines Exhaustive ammination, High
Purification & Characteristics Of Organic Compounds Separation and analysis of alcohols and phenols High *
Chemistry Of Representative Elements Silicon, Structure of oxides and oxyacids High
Coordination Chemistry & Organo-Metallic Compounds Colour and Magnetic properties, Hybridization High
Qualitative Analysis IInd and IVth group Analysis High

2. Students must not try to learn new things at this stage. They should try to consolidate whatever they already know. In the paper a score of about 45% to 50% will be good enough.
3. Over the years, in chemistry, questions have been repeatedly asked on electrochemistry, thermodynamics, ionic equilibrium, states of matter, chemical bonding and organic chemistry. If we cover these topics thoroughly you would be able to secure 50% marks easily
4. In organic chemistry, reaction mechanism, particularly those involving reactions of alekenes, alkynes, alcohols and carbon compounds are the most important areas in which students are tested. Another important topic is strength of organic acids and bases.
Biomolecules is also becoming increasingly popular with JEE question setters.
5. In inorganic chemistry qualitative analysis, coordination compound, Periodic properties and extraction of metals are particularly important. Apart from that questions are also asked from general properties of s, p, d & f block element.

Crack Maths @ IIT

1. Mathematics paper has often been more difficult than the other two subjects (Physics & Chemistry).
2. Very often a Maths problem can be solved using a number of ways - only one way will be the shortest and most elegant. So, it might help if a student spends a few seconds after reading a question thinking which may be the shortest way to do the problem. Understanding the graph of a function can be very helpful.
3. Following will be the marks-wise breakup for topics:

Topic Marks
Algebra 30%
Trigonometry 5%
Two dimensional geometry 20%
Three Dimensional geometry 5%
Differential Calculus 19%
Integral Calculus 18%
Vectors 3%

While all topics are important, based on analysis of past years papers, following sub-topics have a higher probability of figuring in the paper:

Topic Sub-topic Probability
Algebra Complex Numbers: Geometry High
Algebra Binomial Theorem: binomial coeff. High
Trigonometry Properties of Triangle High
Trigonometry Inverse Trigonometric functions High
2D Geometry Locus Problems on Circles/straight lines High
2D Geometry Conic Sections: Parabola, Ellipse High
Differential Calculus Real Functions Properties High
Differential Calculus Applications of derivatives montonicity High
Integral Calculus Definite Integrals properties High
Integral Calculus Differential Equations evaluation High
Vectors Vector Product High
3D Geometry Straight line in symmetric form High

Crack Physics @ IIT
1. Pattern for the JEE 2009 is expected to be similar to that in 2008. However, following may be the marks-wise breakup for topics:

Topic Marks
Measurements & errors 5%
Mechanics 30%
Waves & Sound 7%
Heat & Thermodynamics 8%
Electricity & Magnetism 25%
Optics 10%
Modern Physics 15%

2. While all topics are important, based on analysis of past years’ papers, following sub-topics have a higher probability of figuring in the paper:

Topic Sub-topic Probability
Measurements Vernier Calipers & Searls appratus. High
Kinematics Relative Velocity, Projectiles High
Properties of Matter Surface Tension, Viscosity High
Waves Resonance Column, Organ Pipes High
Thermal Physics Heat Transfer, Newton’s Law of Cooling High
Electrostatics Field, Capacitors High
Electric Current Kirchoff’s Laws High
Magnetism Magnetic Field due to Current & torque High
EMI, AC AC Circuit High
Optics Young’s Double Slit Experiment High
Modern Physics Photoelectric Effect, X-Rays High

3. Students must not try to learn new things at this stage. They should try to consolidate whatever they already know. In the paper a score of about 40% or 45% will be good enough.

4. Since the pattern will be new, students must be prepared to face any type of questions. However, irrespective of the question type, these will test the understanding and ability to apply basic knowledge.

SN1 and E1 Reactions

2009-03-09T07:51:00.000-07:00

SN2 and E2 vs. SN1 and E1

The SN2 and E2 mechanisms require a good nucleophile or a strong base. In contrast, SN1 and E1 mechanisms need weak nucleophiles and bases.

The nucleophiles and bases in SN1 and E1 reactions aren't strong enough to eject the leaving group by themselves. Instead, both SN1 and E1 reactions are characterized by the formation of a common carbocation intermediate. Even weak bases and poor nucleophiles will react with the carbocation.

Consequences of the Carbocation Intermediate

The carbocation intermediate lends a number of unique features to SN1 and E1 reactions. First, both mechanisms require a stable carbocation intermediate. Thus SN1 and E1 will only work for secondary or tertiary α-carbons**. Second, SN1 and E1 reactions involve a carbocation intermediate and are not concerted. Because of the geometry of the carbocation and their non- concerted nature, both reactions result in a loss of stereochemical configuration. Third, SN1 and E1 reactions are favored by polar, protic solvents. Polar, protic solvents stabilize the carbocation. Fourth, secondary carbocations may rearrange to form tertiary carbocations. This greatly increases the number of products.
Sn1E1 Reactions

Terms

Bimolecular - Involving two molecules. The term bimolecular is used to refer to SN2 and E2 reactions. The rate-limiting transition states of both reactions involve two molecules.

Carbocation - A carbon that carries a positive charge. Carbocations are highly unstable and are prone to rearrangement. SN1 and E1 reactions proceed through a common carbocation intermediate.

E1 - A reaction where a β-hydrogen is Eliminated to form a double bond. E1 reactions go through a carbocation intermediate. Somewhat similar to the E2 reaction.

SN1 - A reaction in which a Nucleophile Substitutes for a leaving group. SN1. It goes through a carbocation intermediate.

Secondary - A secondary carbon has bonds to two other carbons.

Tertiary - A tertiary carbon has bonds to three other carbons.

Unimolecular - Involving one molecule. This term is used synonymously with the E1 and SN1 reactions in this PKB's Note. The rate-limiting transition states of both mechanisms involve one molecule.

Quarks

2009-02-19T11:05:00.000-08:00

Quarks are one type of matter particle. Most of the matter we see around us is made from protons and neutrons, which are composed of quarks. There are six quarks, but physicists usually talk about them in terms of three pairs: up/down, charm/strange, and top/bottom. (Also, for each of these quarks, there is a corresponding antiquark.) Be glad that quarks have such silly names -- it makes them easier to remember! Quarks have the unusual characteristic of having a fractional electric charge, unlike the proton and electron, which have integer charges of +1 and -1 respectively. Quarks also carry another type of charge called color charge.The most elusive quark, the top quark, was discovered in 1995 after its existence had been theorized for 20 years.

Strongest acid

2009-02-19T11:01:00.001-08:00

The strongest used to be fluorosulfuric acid (HFSO3), but the carborane superacids are hundreds of times stronger than fluorosulfuric acid and over a million times stronger than concentrated sulfuric acid. The superacids readily release protons, which is a slightly different criterion for acid strength than the ability to dissociate to release a H+ ion (a proton).

The new “strong-yet-gentle” acids are called carborane acids. The secret to their strength is twofold. Most importantly, the carborane part of the acid is an extremely weak base (i.e. weakly alkaline), weaker than the fluorosulfate part of fluorosulfuric acid, which was the previous record holder for the strongest acid. Secondly, carboranes have extraordinary chemical stability.

Thermodynamics

2009-02-19T10:57:00.000-08:00

INTRODUCTION Thermodynamics, field of physics that describes and correlates the physical properties of macroscopic systems of matter and energy. The principles of thermodynamics are of fundamental importance to all branches of science and engineering.A central concept of thermodynamics is that of the macroscopic system, defined as a geometrically isolable piece of matter in coexistence with an infinite, unperturbable environment. The state of a macroscopic system in equilibrium can be described in terms of such measurable properties as temperature, pressure, and volume, which are known as thermodynamic variables. Many other variables (such as density, specific heat, compressibility, and the coefficient of thermal expansion) can be identified and correlated, to produce a more complete description of an object and its relationship to its environment.When a macroscopic system moves from one state of equilibrium to another, a thermodynamic process is said to take place. Some processes are reversible and others are irreversible. The laws of thermodynamics, discovered in the 19th century through painstaking experimentation, govern the nature of all thermodynamic processes and place limits on them. II. ZEROTH LAW OF THERMODYNAMICS The vocabulary of empirical sciences is often borrowed from daily language. Thus, although the term temperature appeals to common sense, its meaning suffers from the imprecision of nonmathematical language. A precise, though empirical, definition of temperature is provided by the so-called zeroth law of thermodynamics as explained below.When two systems are in equilibrium, they share a certain property. This property can be measured and a definite numerical value ascribed to it. A consequence of this fact is the zeroth law of thermodynamics, which states that when each of two systems is in equilibrium with a third, the first two systems must be in equilibrium with each other. This shared property of equilibrium is the temperature.If any such system is placed in contact with an infinite environment that exists at some certain temperature, the system will eventually come into equilibrium with the environment?that is, reach the same temperature. (The so-called infinite environment is a mathematical abstraction called a thermal reservoir; in reality the environment need only be large relative to the system being studied.)Temperatures are measured with devices called thermometers (see Thermometer). A thermometer contains a substance with conveniently identifiable and reproducible states, such as the normal boiling and freezing points of pure water. If a graduated scale is marked between two such states, the temperature of any system can be determined by having that system brought into thermal contact with the thermometer, provided that the system is large relative to the thermometer. III. FIRST LAW OF THERMODYNAMICS The first law of thermodynamics gives a precise definition of heat, another commonly used concept.When an object is brought into contact with a relatively colder object, a process takes place that brings about an equalization of temperatures of the two objects. To explain this phenomenon, 18th-century scientists hypothesized that a substance more abundant at higher temperature flowed toward the region at a lower temperature. This hypothetical substance, called ?caloric,? was thought to be a fluid capable of moving through material media. The first law of thermodynamics instead identifies caloric, or heat, as a form of energy. It can be converted into mechanical work, and it can be stored, but is not a material substance. Heat, measured originally in terms of a unit called the calorie, and work and energy, measured in ergs, were shown by experiment to be totally equivalent. One calorie is equivalent to 4.186 × 107 ergs, or 4.186 joules.The first law, then, is a law of energy conservation. It states that, because energy cannot be created or destroyed?setting aside the later ramifications of the equivalence of mass and energy (see Nuclear Energy)?the amount of heat transferred into a system plus the amount of work done on the system must result in a corresponding increase of internal energy in the system. Heat and work are mechanisms by which systems exchange energy with one another.In any machine some amount of energy is converted into work; therefore, no machine can exist in which no energy is converted into work. Such a hypothetical machine (in which no energy is required for performing work) is termed a ?perpetual-motion machine of the first kind.? Since the input energy must now take heat into account (and in a broader sense chemical, electrical, nuclear, and other forms of energy as well), the law of energy conservation rules out the possibility of such a machine ever being invented. The first law is sometimes given in a contorted form as a statement that precludes the existence of perpetual-motion machines of the first kind. IV. SECOND LAW OF THERMODYNAMICS The second law of thermodynamics gives a precise definition of a property called entropy. Entropy can be thought of as a measure of how close a system is to equilibrium; it can also be thought of as a measure of the disorder in the system. The law states that the entropy?that is, the disorder?of an isolated system can never decrease. Thus, when an isolated system achieves a configuration of maximum entropy, it can no longer undergo change: It has reached equilibrium. Nature, then, seems to ?prefer? disorder or chaos. It can be shown that the second law stipulates that, in the absence of work, heat cannot be transferred from a region at a lower temperature to one at a higher temperature.The second law poses an additional condition on thermodynamic processes. It is not enough to conserve energy and thus obey the first law. A machine that would deliver work while violating the second law is called a ?perpetual-motion machine of the second kind,? since, for example, energy could then be continually drawn from a cold environment to do work in a hot environment at no cost. The second law of thermodynamics is sometimes given as a statement that precludes perpetual-motion machines of the second kind. V. THERMODYNAMIC CYCLES Carnot Engine Carnot Engine The idealized Carnot engine was envisioned by the French physicist Nicolas Léonard Sadi Carnot, who lived during the early 19th century. The Carnot engine is theoretically perfect, that is, it converts the maximum amount of energy into mechanical work. Carnot showed that the efficiency of any engine depends on the difference between the highest and lowest temperatures reached during one cycle. The greater the difference, the greater the efficiency. An automobile engine, for example, would be more efficient if the fuel burned hotter and the exhaust gas came out of the cylinder at a lower temperature. . Full Size All important thermodynamic relations used in engineering are derived from the first and second laws of thermodynamics. One useful way of discussing thermodynamic processes is in terms of cycles?processes that return a system to its original state after a number of stages, thus restoring the original values for all the relevant thermodynamic variables. In a complete cycle the internal energy of a system depends solely on these variables and cannot change. Thus, the total net heat transferred to the system must equal the total net work delivered from the system.An ideal cycle would be performed by a perfectly efficient heat engine?that is, all the heat would be converted to mechanical work. The 19th-century French scientist Nicolas Léonard Sadi Carnot, who conceived a thermodynamic cycle that is the basic cycle of all heat engines, showed that such an ideal engine cannot exist. Any heat engine must expend some fraction of its heat input as exhaust. The second law of thermodynamics places an upper limit on the efficiency of engines; that upper limit is less than 100 percent. The limiting case is now known as a Carnot cycle. VI. THIRD LAW OF THERMODYNAMICS The second law suggests the existence of an absolute temperature scale that includes an absolute zero of temperature. The third law of thermodynamics states that absolute zero cannot be attained by any procedure in a finite number of steps. Absolute zero can be approached arbitrarily closely, but it can never be reached. VII. MICROSCOPIC BASIS OF THERMODYNAMICS The recognition that all matter is made up of molecules provided a microscopic foundation for thermodynamics. A thermodynamic system consisting of a pure substance can be described as a collection of like molecules, each with its individual motion describable in terms of such mechanical variables as velocity and momentum. At least in principle, it should therefore be possible to derive the collective properties of the system by solving equations of motion for the molecules. In this sense, thermodynamics could be regarded as a mere application of the laws of mechanics to the microscopic system.Objects of ordinary size?that is, ordinary on the human scale?contain immense numbers (on the order of 1024) of molecules. Assuming the molecules to be spherical, each would need three variables to describe its position and three more to describe its velocity. Describing a macroscopic system in this way would be a task that even the largest modern computer could not manage. A complete solution of these equations, furthermore, would tell us where each molecule is and what it is doing at every moment. Such a vast quantity of information would be too detailed to be useful and too transient to be important.Statistical methods were devised therefore to obtain averages of the mechanical variables of the molecules in a system and to provide the gross features of the system. These gross features turn out to be, precisely, the macroscopic thermodynamic variables. The statistical treatment of molecular mechanics is called statistical mechanics, and it anchors thermodynamics to mechanics.Viewed from the statistical perspective, temperature represents a measure of the average kinetic energy of the molecules of a system. Increases in temperature reflect increases in the vigor of molecular motion. When two systems are in contact, energy is transferred between molecules as a result of collisions. The transfer will continue until uniformity is achieved, in a statistical sense, which corresponds to thermal equilibrium. The kinetic energy of the molecules also corresponds to heat and?together with the potential energy arising from interaction between molecules?makes up the internal energy of a system.The conservation of energy, a well-known law of mechanics, translates readily to the first law of thermodynamics, and the concept of entropy translates into the extent of disorder on the molecular scale. By assuming that all combinations of molecular motion are equally likely, thermodynamics shows that the more disordered the state of an isolated system, the more combinations can be found that could give rise to that state, and hence the more frequently it will occur. The probability of the more disordered state occurring overwhelms the probability of the occurrence of all other states. This probability provides a statistical basis for definitions of both equilibrium state and entropy.Finally, temperature can be reduced by taking energy out of a system, that is, by reducing the vigor of molecular motion. Absolute zero corresponds to the state of a system in which all its constituents are at rest. This is, however, a notion from classical physics. In terms of quantum mechanics, residual molecular motion will exist even at absolute zero. An analysis of the statistical basis of the third law goes beyond the scope of the present discussion

Applications to the physical equilibrium : Le-Chatelier's principle

2009-02-18T11:13:00.000-08:00

Applications to the physical equilibrium : Le-Chatelier's principle is applicable to the physical equilibrium in the following manner;

(i) Melting of ice (Ice – water system) : ⇌

(In this reaction volume is decreased from 1.09 c.c. to 1.01 c.c. per gm.)

(a) At high temperature more water is formed as it absorbs heat. (b) At high pressure more water is formed as it is accompanied by decrease in volume.(c) At higher pressure, melting point of ice is lowered, while boiling point of water is increased.

(ii) Melting of sulphur :⇌

(This reaction accompanies with increase in volume.)

(a) At high temperature, more liquid sulphur is formed. (b) At higher pressure, less sulphur will melt as melting increases volume.(c) At higher pressure, melting point of sulphur is increased.

(iii) Boiling of water (water- water vapour system) : ⇌

(It is accompanied by absorption of heat and increase in volume.)

(a) At high temperature more vapours are formed.(b) At higher pressure, vapours will be converted to liquid as it decreases volume.(c) At higher pressure, boiling point of water is increased (principle of pressure cooker).

(iv) Solubility of salts : If solubility of a salt is accompanied by absorption of heat, its solubility increases with rise in temperature; e.g., etc.

On the other hand if it is accompanied by evolution of heat, solubility decreases with increase in temperature; e.g., etc.

Regards
Pawan Sir

for detail concepts.............
Boiling and freezing: the effects of solutes and of pressure
Why does adding solutes and applying pressure affect boiling and freezing temperatures? This page gives a simple, non-mathematical explanation. Although the phenomena are more general, water is given as the familiar example, because of questions such as:

* What happens to boiling and freezing when you add solutes (eg sugar or salt) to water?
* Why do they salt the roads when it snows?
* How does antifreeze work?
* How can living tissues survive subzero temperatures?
* Can you make good tea on a mountain top?
* Do skates work by depressing the melting temperature of ice?

(For those looking for formal treatments, these effects are analysed in standard second year physics courses under the headings phase equilibria and the Clausius-Clapeyron equation.)

* Why do substances melt and boil?
* The effects of solutes
* The effect of pressure
* When are the boiling temperature and freezing temperature equal?
* Further complications - superheating and supercooling

Why do substances melt and boil?
To oversimplify only a little, temperature is a measure of how much energy there is in molecular motion. To begin with an explicit example, let's consider water. When water molecules are cold enough, they don't have much heat energy so they don't jostle around too much. Consequently, they can pack together in a very organised structure, called ice. At high enough temperatures, they have so much energy that they can escape the attraction of their neighbours. So they form steam, in which the molecules fly all over the place in a very disordered way. At medium temperatures, which means that the molecules have moderate amounts of energy (and if the pressure is high enough*) they form liquid water. Here the molecules have enough energy to move around, but not enough to escape from their neighbours entirely. Molecules in liquid water are more ordered than in steam but less ordered than ice. (As an example of the order in a liquid, we can observe that the centre of each molecule is about one molecular diameter away from that of its nearest neighbours.)

Why is the change so sudden? At atmospheric pressure, water melts at 0°C and boils at 100°C. What determines the melting point and the boiling point?

The answer is a trade-off between the molecular energy (which we notice as temperature) and the molecular order: the difference between highly organised structure in ice, rather close packing in liquid water, and nearly complete disorganisation in steam. At 0°C and 100°C, the order effect and the energy effect are exactly balanced, and so ice and water co-exist at 0°C, water and steam coexist at 100°C (at atmospheric pressure).

The crystalline structure of ice is rather difficult to show in two dimensions, so the sketches below show, schematically, a simpler crystal, liquid and vapour phase. The patterened circles represent (rather simplistically) the substance in whose melting and evaporation we are interested. The coloured circles represent molecules of the air (mainly nitrogen). The black circles (next picture) represent solutes. The sketches are not to scale.

Schematic of crystal, pure liquid and gas

The effects of solutes
What happens if, instead of having pure liquid water, we put some salt or sugar in the water? In other words, what if our liquid phase is a solution? This makes the liquid state less organised, because the sugar molecules or salt ions are free to move about almost randomly. So the liquid water molecules are more disordered (less regimented) in a solution. The ice and the steam remain unaffected however: sugar and salt hardly dissolve at all in ice, nor do they evaporate near 100°C.

Schematic of crystal, solution and gas

How does this affect the trade-off between the molecular energy and the molecular order? The gain in disorder on evaporation is now less, because the liquid water in solution is more disordered. The energy effect is hardly changed, so the energy effect dominates over a slightly larger range: the molecules of water in solution have to have slightly more energy (a slightly higher temperature) in order for the two effects to be in balance. So the boiling temperature is higher for a solution.

Conversely, when we look at melting, the disorder effect is greater for a solution: on melting into a solution, water molecules go from the high order of crystalline ice into an even more disordered state than pure liquid. So the disorder effect can dominate even at lower temperatures. So the freezing temperature is lower for a solution.

An aqueous solution has a higher boiling point and a lower freezing point than does pure water.
If the solution is not too concentrated, these two effects are approximately independent of what the dissolved substance is: a sugar molecule has much the same effect as a salt ion. So, provided you remember to count each ion separately, the effect of concentration on boiling point elevation or freezing point depression is much the same for all small solutes in water. (Macromolecules such as polymers behave differently because they have lots of neighbouring solvent molecules, and so affect the solvent much more than simple solutes.)

So, you might expect that the antifreeze in a radiator not only stops it freezing, but also helps stop it from boiling. However, the real situation is more complicated: antifreeze has the disadvantage that it is not quite so good at transporting heat. Ethylene glycol is one antifreeze. Salt is used to melt snow and ice on roads in cold countries, but it is not used in radiators because it is corrosive and crystallises readily. Sugar is not used in some applications, because concentrated sugar solutions are viscous, and because they support bugs. However, many organisms use sugars and other small organic molecules as antifreeze. See cryobiology.

The effect of pressure
Notice that above I've included the proviso "at atmospheric pressure" a few times. The reason why the pressure is important is that, in the vapour phase, a given amount of a substance occupies a much larger volume than it does as a liquid. Some of the energy required to vapourise it goes towards 'pushing the air out of the way' to make room for the amount evaporated. (The amount of work done is the product of the pressure and the change in volume. Technically, there is a PdV term in the latent heat.) So, at low pressure, it is easier to form the vapour phase and so the boiling point is lower. The dependence of the transition temperature on pressure is the Clausius-Clapeyron effect. (Again, being a bit technical, we note that this effect involves energy - the work done in displacing air - whereas the solute effect involves entropy - the disordering of the liquid phase.)

Water expands a lot when it boils: one kilogram of water is one litre of liquid water, but it becomes about 1700 litres of steam at atmospheric pressure. This means that even modest increases in altitude can measurably reduce the boiling temperature. Some people complain that this affects cooking and even the taste of tea at altitude.

It is also true that pressure changes the melting temperature. However, because the volume occupied by a kg of liquid is not much different from that occupied by a kg of solid, this effect is very small unless the pressures are very large. For most substances, the freezing point rises, though only very slightly, with increased pressure.

Water is one of the very rare substances that expands upon freezing. Consequently, its melting temperature falls very slightly if pressure is increased.

It is sometimes said that freezing point depression with pressure explains the low friction under an ice-skate. I find this difficult to believe. The Clausius-Clapeyron effect appears not large enough to make a noticeable difference. However, the skate story is so widely believed (outside of thermodynamics classes, anyway) that it's worth being quantitative. The Clausius-Clapeyron equation says that the ratio of the change in pressure times the change in specific volume to the latent heat of the phase change equals the ratio of the change in transition temperature to the (absolute) melting or boiling temperature. (It's often written as dP/dT = L/T*Δv.)

The weight of the skater is say 1 kN, which might be concentrated on a skate area of say 100 mm2, so the pressure is increased by (very roughly) 10 MPa. A kg of water (one litre) freezes to give about 1.1 litre of ice, so the change in specific volume is about 10-4 m3kg-1. The latent heat of fusion of ice is 330 kJ.kg-1. So the proportional change in temperature is (10 MPa)(10-4 m3kg-1)/(330 kJ.kg-1), which is 0.3%. Multiply this by the melting temperature of ice (273 K) and we get a temperature change of around 1 K = 1 °C. So, with these values, the calculation shows that the pressure of an ice skate can reduce themelting temperature of ice by not very much more than 1 °C. However, if this were the cause of the slipperiness, ice skating would be possible only at temperatures only one or a few degrees below freezing. From observation, it is possible to ice skate on ice at much lower temperatures than this. Unless we could argue that the area of contact of a skate is as small as 10 mm2, this effect cannot explain why ice is slippery under a skate. On the other hand, it is easy to explain that the surface of ice is at least a little slippery. At the surface of ice, water molecules are only hydrogen bonded to their neighbours on one side. Consequently, their energy is not as low as in bulk ice. So, at equilibrium, they must have a higher entropy. So ice must have a thin water layer on the surface, whose thickness woud be expected to increase at temperatures close to melting.

The comparable calculation for boiling point change is a bit more complicated. The latent heat in this case is larger (2.3 MJ-1) but the change in specific volume is much larger (typically a few times 10-2 m3kg-1). So changes in altitude can change the boiling temperature, and going up a mountain can reduce it by as much as several degrees.

When are the boiling temperature and freezing temperature equal?
For all substances, as we lower pressure, the boiling temperature falls much more rapidly than does the freezing temperature. (For water, the freezing temperature rises slightly at low pressure.) Hence the obvious question: Are the boiling temperature and freezing temperature ever equal?

The answer is yes. At the low pressure of 611 Pa (only 0.006 times atmospheric pressure), pure water boils at 0.01 °C, and it also freezes at 0.01 °C. The combination of conditions (P, T) = (611 Pa, 0.01 °C) is called the triple point of water because, at this pressure and temperature ice, liquid water and steam can coexist in equilibrium. This point is used to define our scale of temperature: by definition, the triple point of water occurs at 273.16 K, where K is the kelvin. 273.16 K = 0.01 °C

* This explains why, above, I wrote that liquid water only exists if the pressure is high enough. At pressures below 611 Pa, there are only two phases, and ice sublimes to form steam directly, without passing through a liquid phase. (In this context, the reverse of 'to sublime' is not, as one might have hoped, 'to ridicule'. At low pressures, steam condenses to form ice.)

Melting Point and Freezing Point

Pure, crystalline solids have a characteristic melting point, the temperature at which the solid melts to become a liquid. The transition between the solid and the liquid is so sharp for small samples of a pure substance that melting points can be measured to 0.1oC. The melting point of solid oxygen, for example, is -218.4oC.

Liquids have a characteristic temperature at which they turn into solids, known as their freezing point. In theory, the melting point of a solid should be the same as the freezing point of the liquid. In practice, small differences between these quantities can be observed.

It is difficult, if not impossible, to heat a solid above its melting point because the heat that enters the solid at its melting point is used to convert the solid into a liquid. It is possible, however, to cool some liquids to temperatures below their freezing points without forming a solid. When this is done, the liquid is said to be supercooled.

An example of a supercooled liquid can be made by heating solid sodium acetate trihydrate (NaCH3CO2 3 H2O). When this solid melts, the sodium acetate dissolves in the water that was trapped in the crystal to form a solution. When the solution cools to room temperature, it should solidify. But it often doesn't. If a small crystal of sodium acetate trihydrate is added to the liquid, however, the contents of the flask solidify within seconds.

A liquid can become supercooled because the particles in a solid are packed in a regular structure that is characteristic of that particular substance. Some of these solids form very easily; others do not. Some need a particle of dust, or a seed crystal, to act as a site on which the crystal can grow. In order to form crystals of sodium acetate trihydrate, Na+ ions, CH3CO2- ions, and water molecules must come together in the proper orientation. It is difficult for these particles to organize themselves, but a seed crystal can provide the framework on which the proper arrangement of ions and water molecules can grow.

Because it is difficult to heat solids to temperatures above their melting points, and because pure solids tend to melt over a very small temperature range, melting points are often used to help identify compounds. We can distinguish between the three sugars known as glucose (MP = 150oC), fructose (MP = 103-105oC), and sucrose (MP = 185-186oC), for example, by determining the melting point of a small sample.

Measurements of the melting point of a solid can also provide information about the purity of the substance. Pure, crystalline solids melt over a very narrow range of temperatures, whereas mixtures melt over a broad temperature range. Mixtures also tend to melt at temperatures below the melting points of the pure solids.

return to top

Boiling Point

When a liquid is heated, it eventually reaches a temperature at which the vapor pressure is large enough that bubbles form inside the body of the liquid. This temperature is called the boiling point. Once the liquid starts to boil, the temperature remains constant until all of the liquid has been converted to a gas.

The normal boiling point of water is 100oC. But if you try to cook an egg in boiling water while camping in the Rocky Mountains at an elevation of 10,000 feet, you will find that it takes longer for the egg to cook because water boils at only 90oC at this elevation.

In theory, you shouldn't be able to heat a liquid to temperatures above its normal boiling point. Before microwave ovens became popular, however, pressure cookers were used to decrease the amount of time it took to cook food. In a typical pressure cooker, water can remain a liquid at temperatures as high as 120oC, and food cooks in as little as one-third the normal time.

To explain why water boils at 90oC in the mountains and 120oC in a pressure cooker, even though the normal boiling point of water is 100oC, we have to understand why a liquid boils. By definition, a liquid boils when the vapor pressure of the gas escaping from the liquid is equal to the pressure exerted on the liquid by its surroundings, as shown in the figure below.
graph
Liquids boil when their vapor pressure is equal to the pressure exerted on the liquid by its surroundings.

The normal boiling point of water is 100oC because this is the temperature at which the vapor pressure of water is 760 mmHg, or 1 atm. Under normal conditions, when the pressure of the atmosphere is approximately 760 mmHg, water boils at 100oC. At 10,000 feet above sea level, the pressure of the atmosphere is only 526 mmHg. At these elevations, water boils when its vapor pressure is 526 mmHg, which occurs at a temperature of 90oC.

Pressure cookers are equipped with a valve that lets gas escape when the pressure inside the pot exceeds some fixed value. This valve is often set at 15 psi, which means that the water vapor inside the pot must reach a pressure of 2 atm before it can escape. Because water doesn't reach a vapor pressure of 2 atm until the temperature is 120oC, it boils in this container at 120oC.

Liquids often boil in an uneven fashion, or bump. They tend to bump when there aren't any scratches on the walls of the container where bubbles can form. Bumping is easily prevented by adding a few boiling chips to the liquid, which provide a rough surface upon which bubbles can form. When boiling chips are used, essentially all of the bubbles that rise through the solution form on the surface of these chips.

Phase Diagrams

The figure below shows an example of a phase diagram, which summarizes the effect of temperature and pressure on a substance in a closed container. Every point in this diagram represents a possible combination of temperature and pressure for the system. The diagram is divided into three areas, which represent the solid, liquid, and gaseous states of the substance.

phase diagram

The best way to remember which area corresponds to each of these states is to remember the conditions of temperature and pressure that are most likely to be associated with a solid, a liquid, and a gas. Low temperatures and high pressures favor the formation of a solid. Gases, on the other hand, are most likely to be found at high temperatures and low pressures. Liquids lie between these extremes.

You can therefore test whether you have correctly labeled a phase diagram by drawing a line from left to right across the top of the diagram, which corresponds to an increase in the temperature of the system at constant pressure. When a solid is heated at constant pressure, it melts to form a liquid, which eventually boils to form a gas.

Phase diagrams can be used in several ways. We can focus on the regions separated by the lines in these diagrams, and get some idea of the conditions of temperature and pressure that are most likely to produce a gas, a liquid, or a solid. We can also focus on the lines that divide the diagram into states, which represent the combinations of temperature and pressure at which two states are in equilibrium.

The points along the line connecting points A and B in the phase diagram in the figure above represent all combinations of temperature and pressure at which the solid is in equilibrium with the gas. At these temperatures and pressures, the rate at which the solid sublimes to form a gas is equal to the rate at which the gas condenses to form a solid.
Along AB line:

rate at which solid sublimes to form a gas
=
rate at which gas condenses to form a solid

The solid line between points B and C is identical to the plot of temperature dependence of the vapor pressure of the liquid. It contains all of the combinations of temperature and pressure at which the liquid boils. At every point along this line, the liquid boils to form a gas and the gas condenses to form a liquid at the same rate.
Along BC line:

rate at which liquid boils to form a gas
=
rate at which gas condenses to form a liquid

The solid line between points B and D contains the combinations of temperature and pressure at which the solid and liquid are in equilibrium. At every point along this line, the solid melts at the same rate at which the liquid freezes.
Along BD line:

rate at which solid melts to form a liquid
=
rate at which liquid freezes to form a solid

The BD line is almost vertical because the melting point of a solid is not very sensitive to changes in pressure. For most compounds, this line has a small positive slope, as shown in the figure above. The slope of this line is slightly negative for water, however. As a result, water can melt at temperatures near its freezing point when subjected to pressure. The ease with which ice skaters glide across a frozen pond can be explained by the fact that the pressure exerted by their skates melts a small portion of the ice that lies beneath the blades.

Point B in this phase diagram represents the only combination of temperature and pressure at which a pure substance can exist simultaneously as a solid, a liquid, and a gas. It is therefore called the triple point of the substance, and it represents the only point in the phase diagram in which all three states are in equilibrium. Point C is the critical point of the substance, which is the highest temperature and pressure at which a gas and a liquid can coexist at equilibrium.

The figure below shows what happens when we draw a horizontal line across a phase diagram at a pressure of exactly 1 atm. This line crosses the line between points B and D at the melting point of the substance because solids normally melt at the temperature at which the solid and liquid are in equilibrium at 1 atm pressure. The line crosses the line between points B and C at the boiling point of the substance because the normal boiling point of a liquid is the temperature at which the liquid and gas are in equilibrium at 1 atm pressure and the vapor pressure of the liquid is therefore equal to 1 atm.

phase diagram

The Clausius-Clapeyron Equation

The relationship between the temperature of a liquid and its vapor pressure is not a straight line. The vapor pressure of water, for example, increases significantly more rapidly than the temperature of the system. This behavior can be explained with the Clausius-Clapeyron equation.
equation

According to this equation, the rate at which the natural logarithm of the vapor pressure of a liquid changes with temperature is determined by the molar enthalpy of vaporization of the liquid, the ideal gas constant, and the temperature of the system. If we assume that Hvap does not depend on the temperature of the system, the Clausius-Clapeyron equation can be written in the following integrated form where C is a constant.
equation

This form of the Clausius-Clapeyron equation has been used to measure the enthalpy of vaporization of a liquid from plots of the natural log of its vapor pressure versus temperature. For our purposes, it would be more useful to take advantage of logarithmic mathematics to write this equation as follows.
equation

Because the molar enthalpy of vaporization of a liquid is always a positive number, this equation suggests that the logarithm of the vapor pressure will increase as the temperature of the system increases. Since the vapor pressure of the liquid increases much more rapidly than its natural logarithm, we get the behavior observed in the plot of vapor pressure versus temperature.

TOP TEN TIPS TO CRACK IIT-JEE

2009-02-17T23:47:00.000-08:00

TOP TEN TIPS TO CRACK IIT-JEE

1.First and most important is to have confidence in yourself.Don’t lose that confidence while preparing for the entrance exams even if you are not doing well in the coaching classes.

2.Having mentioned about coaching classes,I would say they play an important role in helping you crack the exam.The simple reason being continued guidance throughout the year and perpetual tests that keep you in touch with course all the time.Hence it is important to be regular in them to be able to achieve good results in the end.

3.At home prepare a time table and follow it strictly.Don’t ignore it.

4.Don’t get too involved with only engineering books and refer to NCERT books too.With the new IIT pattern, a lot of questions are directly made from there which you might have already seen yourself by analyzing this year’s paper.

5.Don’t waste time and don’t stress yourself.Study in a balanced way and maintain a good friend circle who will guide you when you face doubts and also boost your morale.

6.This one is for toppers!Don’t get complacent.Many good rankers in coaching institutes get complacent if they good marks which in is bad in the long run as they lose out to lower rankers in the end.I have seen many cases.

7.To crack big papers it is very very important to be able to solve the paper completely.You might know all the questions but not been able to solve them is equivalent to not knowing them.So the golden rule is practice a lot of sample papers and in the exams not to waste time on a single question.

8.Stay away from computers as much as possible! This is a major distraction from students from towns and cities as you don’t get to know how quickly time is slipping out of your hands along with straining your eyes and body which makes you dizzy and you are off to sleep!

9.Choosing the right books for entrance exams is very important.Consult IITians and your teachers about them to make sure that you get your hands on the right ones and don’t waste your time in trying out new books every time.

10.Last but very important point is not to get nervous while going for the exam.This will get your hands and brain move faster,quicker and better than those who are nervous!

WHEN STARTING PREPARING FOR IIT-JEE

2009-02-17T23:46:00.001-08:00

The best way to crack IIT-JEE is its early planning. IIT-JEE is not about what you have studied in your coaching institute. It is about what you have studied in your whole life.

Best time to start preparation after 10^th standard because at the end of board exams you feel fresh so it is best time to start preparation for IIT-JEE. When you take admission in 11^th standard study seriously for 11^th standard because when you are studying for 11^th standard indirectly studying for IIT-JEE because IIT-JEE syllabus include 11^th and 12^th syllabus. If you are student of CBSE board then you have nothing to study more than extra than your syllabus because syllabus of IIT-JEE is totally depend upon CBSE board. If you are student of state board take 11^th and 12^th standard seriously and start referring CBSE board books simultaneously.

At the starting stage of IIT –JEE preparation start to clear your basic concept on mathematic, basic science which you have studied in your 9^th and 10^th standard. Clear you’re all doubt about basic thing. Create a strong base for IIT-JEE suppose if you want to construct any building or home first and only important thing comes in your mind is it’s base or foundation so create a strong foundation on which IIT-JEE stand |

Gearing up for IIT-JEE

2009-02-17T23:44:00.000-08:00

Strategies

The initial preparation should have been aimed at getting maximum practise in solving actual question that were asked for the IIT-JEE point of view.

Now the emphasis should be on tackling similar problems in a much more speedier fashion than was done by the candidate before.

for this to happen , a serious candidate of the IIT-JEE must make sure that he or she takes as many ' simulated test' as possible;either those administered by coaching institutes or by agencies engaged in providing correspondence courses for IIT-JEE training. according to expert , this heps a candidate correlated his problem solving skills with the time available for the same at the IIT-JEE.

Analysing Preparation
This is also a time for a candidate to pause in his preparation and gauge how sound his understanding of the concepts in each subject is.

for doing this , tough , the candidate has got to constantly look at the IIT-JEE syllabus to find out how much he/she needs to know on any given topic.

"conceptual clarity is very important at every stage of preparation for the IIT_jee, more so , in the month leading up to the actual test. instead of merely knowing the equations for a chemical reaction or for solving a problem in mathematics,a candidate for the IIT-JEE should know the 'why inside every equation, for this to happen , knowing the concept from which equation are derived is an essential prerequisite.

Integrating Knowledge.

The IIT-JEE is also all about integrating the knowledge a candidate has on various subjects.
inevitably the concept that a candidate learns are also associated with these 'parts' of the subject. at the IIT-JEE, though the candidate would have to integrate the knowledge gained from these chapters and apply them to find the answer to a question.

More ever, the student must also be adept at juggling concept,factoring in one concept and its equation with another to demonstrate the manner in which he/she ha understood the problem at hand.
In other word, the manner in which a student attempts to solve a problem is equally important for theIIT-JEE,it is said ,as arriving at the right answer.

The 'how' process of answering IIT-JEE question may be finetuned by breaking down a candidate's method of attempting to solve a problem into small parts.
Any unnecessary steps can then be identified , way to compress a couple or more steps into one may be found.
Self Confidence.
It is very important to believe in yourself while preparing for IIT-JEE. self confidence mean believe in yourself that" i will crack IIT-JEE"

DNA, RNA, QUIZ, BIOCHEMISTRY

2008-11-28T07:49:00.000-08:00

1. Because each base pairs with a complementary base, in every DNA molecule the amount of
a. cytosine equals that of guanine.
b. cytosine equals that of thymine.
c. cytosine equals that of adenine.
d. each nucleotide is unrelated to all others.
e. each nucleotide is equal to all others.

2. Semiconservative replication refers to the fact that:
a. each new DNA molecule contains two new single DNA strands.
b. DNA polymerase uses free nucleotides to synthesize new DNA molecules.
c. certain bases pair with specific bases.
d. each parental DNA strand is joined with a new strand containing complementary base pairs.
e. mistakes are made during DNA replication.

3. Which of the following are INCORRECTLY matched?
a. Complementary base pairs: adenine and cytosine
b. Bases: adenine, thymine, cytosine, and guanine
c. Nucleotide: phosphate and sugar and base
d. Eukaryotic chromosome: DNA and protein
e. Enzymes involved in DNA replication: DNA polymerase and DNA helicase

4. Which component of a nucleotide, present within a DNA molecule, could be removed without breaking the polynucleotide chain?
a. ribose
b. deoxyribose
c. phosphate
d. uracil
e. thymine

5. What is the relationship among DNA, a gene, and a chromosome?
a. A chromosome contains hundreds of genes which are composed of protein.
b. A chromosome contains hundreds of genes which are composed of DNA.
c. A gene contains hundreds of chromosomes which are composed of protein.
d. A gene is composed of DNA, but there is no relationship to a chromosome.
e. A gene contains hundreds of chromosomes which are composed of DNA.

6. Which of the following can cause errors to accumulate in DNA?
a. High levels of metabolic activity
b. Ultraviolet light
c. Cold temperatures
d. A lack of water and oxygen

7. How many different three-base sequences can be assembled using the four nucleotides found in DNA?
a. 1 b. 3 c. 9 d. 64 e. more than 64

8. What is the function of DNA polymerase in DNA replication?
a. Destroy old DNA
b. Synthesize new DNA strands
c. Join together segments of DNA
d. Separate the 2 parental DNA strands
e. None of the above

9. A forensic scientist determining whether DNA found at a scene matches that of a suspect would be most interested in the suspect’s __________.
a. DNA sequence
b. Proportion of A, C, T, and G bases
c. Hair color
d. Chromosome size
e. Number of DNA bases

10. If a base sequence contains 20% adenine, what is the percentage of guanine?
a. 20%
b. 30%
c. 40%
d. 50%
e. 80%

Bio 103 Practice Quiz – Chapter 9 Name_____________________

Turn in both quizzes for two extra points on Exam 5

1. When comparing DNA and RNA, we find
a. no sugar is present in either molecule.
b. hydrogen bonding is important only in DNA.
c. only DNA has a backbone of sugars and phosphates.
d. adenine pairs with different bases in DNA and RNA.
e. thymine pairs with different bases in DNA and RNA.

2. A "mini-gene" has the following sequence: TACCCGTGCACG. What is the consequence if the T at the beginning of the sequence is deleted?
a. All of the codons after that point will be changed.
b. Only the amino acid encoded by that codon will be changed.
c. RNA polymerase will skip that codon, but all the others will be read normally.
d. RNA polymerase will correct the deletion and a normal protein will be produced.
e. The first nucleotide is not important, so there will be no change.

3. Imagine that the template strand of a gene has the sequence TAC. After RNA is made, what sequence of the anticodon would decode this?
a. ATG, because the anticodon is complementary to the template strand.
b. AUG, because the anticodon is complementary to the template strand (but it has U instead of T).
c. UAC, because the anticodon has the same sequence as the template strand (but it has U instead of T).
d. TAC, because the anticodon has the same sequence as the template strand.

4. Imagine that a probe sent to Mars brings back a sample. It contains a very primitive life-form that appears similar to bacteria. Scientists are able to revive it and begin to grow it in culture. Much to their amazement, the DNA of these Martian microbes contains only two nucleotides, and these nucleotides contain bases that are not present in the DNA of organisms on Earth. If the Martian microbe uses a triplet code, what is the maximum number of different amino acids that it can have in its proteins?
a. 9, because 32 = 3 x 3 = 9
b. 16, because 42 = 4 x 4 = 16
c. 8, because 23 = 2 x 2 x 2 = 8
d. 7, because there are 8 possible codons (23 = 2 x 2 x 2 = 8) but at least one of the codons must be a stop.

5. What is the promoter region?
a. It is a region of RNA that binds to the RNA polymerase and initiates transcription.
b. It is a component of each type of RNA.
c. It is responsible for the selective nature of transcription.
d. It is a region of a parent DNA strand that binds to the RNA polymerase to initiate transcription.

6. Which of the following is NOT a means of regulating gene expression?
a. Regulating the life span of a protein
b. Modifying proteins after they are synthesized
c. Varying the rate at which messenger RNAs are translated
d. Varying the rate at which messenger RNAs are transcribed
e. Deleting genes from cells in which they are not needed

7. What kind of mutation would have the most dramatic effect on the protein encoded by that gene?
a. A base substitution
b. A base insertion near the beginning of the coding sequence
c. A base insertion near the end of the coding sequence
d. Deletion of three bases near the start of the coding sequence

8. Which of the following is NOT true about RNA molecules?
a. rRNA and certain proteins together make up the ribosomes
b. tRNAs are translated in the cytoplasm of eukaryotic cells
c. mRNAs are transcribed in the nucleus of eukaryotic cells
d. mRNAs are translated in the cytoplasm of eukaryotic cells

9. How can a gene be mutated with no resulting change in the protein that is produced from that gene?
a. The mutation is in the active site of the protein.
b. A codon has changed, but it codes for the same amino acid as the original codon.
c. An entire codon has been removed.
d. RNA polymerase can edit the mutation from the mRNA produced during translation.
e. This is impossible. All mutations, by definition, result in altered proteins.

10. Of the following types of mutations, which is considered the LEAST drastic?
a. insertion of one base
b. deletion of two bases
c. a neutral base substitution
d. a stop codon
e. a substitution of a hydrophilic amino acid for a hydrophobic one

FOLLOWING PROCEDURE WILL BE EMPLOYED FOR RANKING

2008-11-23T12:50:00.000-08:00

1. Only those candidates who attempt both Paper 1 and
Paper 2 will be considered for the ranking.

2. Marks in each subject like Mathematics, Physics and
Chemistry will be obtained by adding the marks secured in
that subject part in both paper 1 and paper 2. i.e. Marks in
Mathematics will be equal to marks in Mathematics
section of Paper 1 + marks in Mathematics section of
Paper 2. Similar procedure will be followed for Physics and
Chemistry.

3. Subject-wise Cut off- All candidates whose marks are in
the top 80% bracket of the total candidates appeared will
qualify the cut off requirement for that subject for
General / DS category. Candidates meeting the cut off
requirements for all the three subjects will be considered
for the ranking.

4. Subject-wise Cut offs for the reserved category candidates:
There is some relaxation in the subject-wise cut offs
available to reserved category candidates.

5. Based on the aggregate marks secured in the
Examination, a common merit list with AIR will be
prepared without any relaxed criteria. Total number of
candidates declared qualified and ranked will be 1.15
times the total number of seats available at the seven
IITs, IT-BHU and ISMU.

6. Reserved Category Merit Lists- In addition to a common
merit list, separate merit lists of candidates belonging to
the SC, ST, and PD categories will be prepared by giving
some further relaxation in the aggregate cut off determined
in 5 above. If a candidate belongs to more than one
reserved category, then he/she for the purpose of ranking
shall be considered in all the categories in which he/she
qualifies.

7. Total number of candidates declared qualified in any
reserved category will not exceed 1.15 times the total
seats available in that category.

2008-11-23T12:44:00.000-08:00

IIT-JEE Important Dates:-

Last date of receipt of completed JEE Application Form at the JEE Office		Wednesday	December 24, 2008
Joint Entrance Examination		Sunday	April 12, 2009
Declaration of Results		Monday	May 25, 2009
Medical Examination and Counselling for Qualified PD Candidates (the Schedule will be announced on the IIT websites)		Tuesday - Thursday	June 9-11, 2009
Counselling (the Schedule will be announced on the IIT websites)	OBC/SC/ST Candidates	Tuesday - Friday	June 9-12, 2009
	GE/DS Candidates	Saturday - Tuesday	June 13 -16, 2009
	Preparatory Courses	Monday	July 6, 2009
Architecture / Design Aptitude Test		Thursday and Monday	June 11 & 15, 2009
Website release of Course Allocation		Wednesday	June 24, 2009

free ebook

2008-11-23T12:28:00.001-08:00

rticles and Books

Introduction to Probability, by Charles Grinstead and J. Laurie Snell

The median isn't the message. by Stephen Jay Gould

Research on the Role of Technology in Teaching and Learning Statistics, edited by Joan B. Garfield and Gail Burrill

Technology in College Statistics Courses, by Joan Garfield, Beth Chance and J. Laurie Snell

Ecological Studies of Wolves on Isle Royale The Isle Royale investigation of wolves and moose represents the world's longest continuous study of either wolves or moose. This is a prime example of a predator-prey relationship, with many years of data.

Does capital punishment deter murder? by John Lamperti

What is a Survey? from the ASA

The chance that an asteroid hits an airplane by William A. Cassidy

Articles and materials relating to specific topics

Texts That Have Been Used in CHANCE Course.

How many times do you have to shuffle a deck of cards? by Brad Mann

How students learn statistics. by Joan Garfield

DNA fingerprinting. National Research Council

How numbers are tricking you Arnold Barnett, Technology Review, October 1994

Madness in the Method Maya Bar-Hillel and Avishai Margali, December 1999

probability book

2008-11-23T12:25:00.001-08:00

http://www.dartmouth.edu/%7Echance/teaching_aids/books_articles/probability_book/book.html

This introductory probability book, published by the American Mathematical Society, is available from AMS bookshop. It has, since publication, also been available for download here in pdf format. We are pleased that this has made our book more widely available.

We are pleased to announce that our book has now been made freely redistributable under the terms of the GNU Free Documentation License (FDL), as published by the Free Software Foundation. Briefly stated, the FDL permits you to do whatever you like with a work, as long as you don't prevent anyone else from doing what they like with it. This is the same license that is used for the Wikipedia. Here is the GNU version in pdf, and here is the source",

Thanks: We owe our ability to distribute this work under the FDL to the far-sightedness of the American Mathematical Society. We are particularly grateful for the help and support of John Ewing, AMS Executive Director and Publisher.

more about iit and paper

2008-11-23T10:32:00.000-08:00

A. DATE OF IIT-JEE.

B. JEE-SYLLABUS IN CHEMISTRY.

C. JEE- PREVIOUS YEARS QUESTIONS IN CHEMISTRY.

D . QUESTION PAPER ANALYSIS IN CHEMISTRY.

ABOUT IIT-JEE

The Indian Institutes of Technology (IITs) need no introduction. It was established to create an environment conducive to the formation of world class Engineers and Technologists, the standards of excellence maintained by these institutes are recognized and respected by the world over. Every year the IITs conduct a Joint Entrance Examination (JEE), to select candidates for the four year B.Tech., B. Pharm., five year B.Arch., M.Tech. and M.Sc. courses offered at their campuses located in Chennai, Delhi, Guwahati, Kanpur, Kharagpur, Mumbai & Roorkee. This year (2008) ,it is being started in Andhra Pradesh , Bihar & Rajasthan.

A. DATE OF IIT-JEE.

2008-JEE 13th APRIL 2008
PATTERN OF JEE-2008
Question Papers
There will be two question papers, each of three hours duration. Both the question papers would consist of three separate sections on Physics, Chemistry, and Mathematics. Questions in these papers will be of objective type, which are to be answered on a specially designed machine-gradable sheet (ORS – Optical Response Sheet) using HB pencils only. Incorrect answers will be awarded negative marks.
Language and Font of Question Papers:-Candidates can opt for Question Papers either in English or in Hindi. This option should be exercised while filling the application form, and it cannot be changed at any later stage. Visually impaired candidates will be provided with question papers with 20% enlarged font. However, to avail this facility, candidates should make a request along with the application form.
Calculators and Log Tables
Use of calculators and log tables is NOT permitted in JEE-2008.

2009-JEE

NOT DECLARED

TOP

B. JEE-SYLLABUS IN CHEMISTRY.

Distributed with XI th & XII C.B.S.E. Syllabus.

Physical Chemistry Syllabus.
xi1. Gaseous and liquid states: Absolute scale of temperature, ideal gas equation; Deviation from ideality, van der Waals equation; Kinetic theory of gases, average, root mean square and most probable velocities and their relation with temperature; Law of partial pressures; Vapour pressure; Diffusion of gases.
xi2. Atomic structure and chemical bonding: Bohr model, spectrum of hydrogen atom, quantum numbers; Wave-particle duality, de Broglie hypothesis; Uncertainty principle; Quantum mechanical picture of hydrogen atom (qualitative treatment), shapes of s, p and d orbitals; Electronic configurations of elements (up to atomic number 36); Aufbau principle; Pauli's exclusion principle and Hund's rule;Orbital overlap and covalent bond; Hybridisation involving s, p and d orbitals only; Orbital energy diagrams for homonuclear diatomic species; Hydrogen bond; Polarity in molecules, dipole moment (qualitative aspects only); VSEPR model and shapes of molecules (linear, angular, triangular, square planar, pyramidal, square pyramidal, trigonal bipyramidal, tetrahedral and octahedral).
xi3. Energetics: First law of thermodynamics; Internal energy, work and heat, pressure-volume work; Enthalpy, Hess's law; Heat of reaction, fusion and vapourization; Second law of thermodynamics; Entropy; Free energy; Criterion of spontaneity.
xi4 Chemical equilibrium: Law of mass action; Equilibrium constant, Le Chatelier's principle (effect of concentration, temperature and pressure); Significance of .G and .Go in chemical equilibrium; Solubility product, common ion effect, pH and buffer solutions; Acids and bases (Bronsted and Lewis concepts); Hydrolysis of salts.
xii5. Electrochemistry: Electrochemical cells and cell reactions; Electrode potentials; Nernst equation and its relation to .G; ; Electrochemical series, emf of galvanic cells; Faraday's laws of electrolysis; Electrolytic conductance, specific, equivalent and molar conductance, Kohlrausch's law; Concentration cells.
xii6. Chemical kinetics: Rates of chemical reactions; Order of reactions; Rate constant; First order reactions; Temperature dependence of rate constant (Arrhenius equation).
xii7. Solid state: Classification of solids, crystalline state, seven crystal systems (cell parameters a, b, c, α,β, γ), close packed structure of solids (cubic), packing in fcc, bcc and hcp lattices; Nearest neighbours, ionic radii, simple ionic compounds, point defects.
xii8. Solutions: Raoult's law; Molecular weight determination from lowering of vapor pressure, elevation of boiling point and depression of freezing point.
xii9. Surface chemistry: Elementary concepts of adsorption (excluding adsorption isotherms); Colloids: types, methods of preparation and general properties; Elementary ideas of emulsions, surfactants and micelles (only definitions and examples).
xii10. Nuclear chemistry: Radioactivity: isotopes and isobars; Properties of α, β, and γ Kinetics of radioactive decay (decay series excluded), carbon dating; Stability of nuclei with respect to proton-neutron ratio; Brief discussion on fission and fusion reactions.
Inorganic Chemistry Syllabus.
1. Isolation/preparation and properties of the following non-metals: Boron, silicon, nitrogen,phosphorus, oxygen, sulphur and halogens; Properties of allotropes of carbon(only diamond and graphite), phosphorus and sulphur.
xii2. Preparation and properties of the following compounds: Oxides, peroxides, hydroxides,carbonates, bicarbonates, chlorides and sulphates of sodium, potassium, magnesium and calcium; Boron: diborane, boric acid and borax; Aluminium: alumina, aluminium chloride and alums; Carbon: oxides and oxyacid (carbonic acid); Silicon: silicones, silicates and silicon carbide; Nitrogen: oxides, oxyacids and ammonia; Phosphorus: oxides, oxyacids (phosphorus acid, phosphoric acid) and phosphine; Oxygen: ozone and hydrogen peroxide; Sulphur: hydrogen sulphide, oxides, sulphurous acid, sulphuric acid and sodium thiosulphate; Halogens: hydrohalic acids, oxides and oxyacids of chlorine, bleaching powder; Xenon fluorides; Fertilizers: commercially available (common) NPK type.
xii3. Transition elements (3d series): Definition, general characteristics, oxidation states and their stabilities, colour (excluding the details of electronic transitions) and calculation of spin-only magnetic moment; Coordination compounds: nomenclature of mononuclear coordination compounds, cis-trans and ionisation isomerisms, hybridization and geometries of mononuclear coordination compounds (linear, tetrahedral, square planar and octahedral).
4. Preparation and properties of the following compounds: Oxides and chlorides of tin and lead;Oxides, chlorides and sulphates of Fe²⁺, Cu²⁺ and Zn²+; Potassium permanganate, potassium dichromate, silver oxide, silver nitrate, silver thiosulphate.
xii5. Ores and minerals: Commonly occurring ores and minerals of iron, copper, tin, lead, magnesium, aluminium, zinc and silver.
xii6. Extractive metallurgy: Chemical principles and reactions only (industrial details excluded); Carbon reduction method (iron and tin); Self reduction method (copper and lead); Electrolytic reduction method (magnesium and aluminium); Cyanide process (silver and gold).
7. Principles of qualitative analysis: Groups I to V (only Ag⁺, Hg²⁺, Cu²⁺, Pb²⁺, Bi³⁺, Fe³⁺, Cr³⁺, Al³⁺, Ca²⁺, Ba²⁺, Zn²⁺, Mn²⁺ and Mg²⁺); Nitrate, halides (excluding fluoride), sulphate, sulphide and sulphite.

Organic Chemistry Syllabus.

xi1.Concepts: Hybridisation of carbon; Sigma and pi-bonds; Shapes of molecules; Structural and geometrical isomerism; Optical isomerism of compounds containing up to two asymmetric centers, (R,S and E,Z nomenclature excluded); IUPAC nomenclature of simple organic compounds (only hydrocarbons, mono-functional and bi-functional compounds); Conformations of ethane and butane (Newman projections);
xiResonance and hyperconjugation; Keto-enol tautomerism; Determination of empirical and molecular formula of simple compounds (only combustion method); Hydrogen bonds: definition and their effects on physical properties of alcohols and carboxylic acids; Inductive and resonance effects on acidity and basicity of organic acids and bases; Polarity and inductive effects in alkyl halides; Reactive intermediates produced during homolytic and heterolytic bond cleavage; Formation, structure and stability of carbocations, carbanions and free radicals.
xi2.Preparation, properties and reactions of alkanes: Homologous series, physical properties of alkanes (melting points, boiling points and density); Combustion and halogenation of alkanes; Preparation of alkanes by Wurtz reaction and decarboxylation reactions.
xi3.Preparation, properties and reactions of alkenes and alkynes: Physical properties of alkenes and alkynes (boiling points, density and dipole moments); Acidity of alkynes; Acid catalysed hydration of alkenes and alkynes (excluding the stereochemistry of addition and elimination); Reactions of alkenes with KMnO4 and ozone; Reduction of alkenes and alkynes; Preparation of alkenes and alkynes by elimination reactions; Electrophilic addition reactions of alkenes with X2, HX, HOX and H2O (X=halogen); Addition reactions of alkynes; Metal acetylides.
xi4.Reactions of benzene: Structure and aromaticity; Electrophilic substitution reactions: halogenation, nitration, sulphonation, Friedel-Crafts alkylation and acylation; Effect of o-, m- and p-directing groups in monosubstituted benzenes.Phenols: Acidity, electrophilic substitution reactions (halogenation, nitration and sulphonation); Reimer-Tieman reaction, Kolbe reaction.
xii5.Characteristic reactions of the following (including those mentioned above): Alkyl halides: rearrangement reactions of alkyl carbocation, Grignard reactions, nucleophilic substitution reactions; Alcohols: esterification, dehydration and oxidation, reaction with sodium, phosphorus halides,ZnCl2/conc.-HCl, conversion of alcohols into aldehydes and ketones; Aldehydes and Ketones: oxidation,reduction, oxime and hydrazone formation; aldol condensation, Perkin reaction; Cannizzaro reaction;haloform reaction and nucleophilic addition reactions (Grignard addition); Carboxylic acids: formation of esters, acid chlorides and amides, ester hydrolysis; Amines: basicity of substituted anilines and aliphatic amines, preparation from nitro compounds, reaction with nitrous acid, azo coupling reaction of diazonium salts of aromatic amines, Sandmeyer and related reactions of diazonium salts; carbylamine reaction; Haloarenes: nucleophilic aromatic substitution in haloarenes and substituted haloarenes -(excluding Benzyne mechanism and Cine substitution).
xii6.Carbohydrates: Classification; mono and di-saccharides (glucose and sucrose); Oxidation, reduction,glycoside formation and hydrolysis of sucrose.
xii7.Amino acids and peptides: General structure (only primary structure for peptides) and physical properties.
xii8.Properties and uses of some important polymers: Natural rubber, cellulose, nylon, teflon and PVC.
9.Practical organic chemistry: Detection of elements (N, S, halogens); Detection and identification of the following functional groups: hydroxyl (alcoholic and phenolic),carbonyl (aldehyde and ketone), carboxyl, amino and nitro; Chemical methods of separation of mono-functional organic compounds from binary mixtures.

C. JEE- PREVIOUS YEARS QUESTIONS IN CHEMISTRY

2007-JEE

2006-JEE

2005-JEE

TOP

D. QUESTION PAPER ANALYSIS IN CHEMISTRY

1. By Type.

PAPER -II

A. Single Choice multiple type Questions --9 Questions [ one correct option out of four]

B. Assertion Reason Type 4 Questions with 4 choice .

C. Paragraph Questions [2 Paragraph each with 3 Questions.]

D. Matrix Matching Questions [3 table matching each with 4 matching sets]

2. By TOPICS.

IIT JEE 2007 Analysis

IIT-JEE 2007 had 2 papers - Paper I and Paper II. The duration of each paper was 3 hours. Each paper consisted of 66 Questions. Both the papers had 3 parts each – Physics, Chemistry and Mathematics. Each part had 22 Questions.

Each of the three parts - Physics, Chemistry and Mathematics - was divided into four sections. The format of the questions in any given section is the same across the three parts (Physics, Chemistry and Mathematics) and across the 2 papers (Paper I and Paper II).
The details of the sections are given below.

	No. of Qns	Title of the Section	Marks per Correct Answer	Number of Choices	Penalty for Wrong Answer	Maximum Marks for the Section
Section 1	9	Straight Objective Type	3	4	-1	27
Section 2	4	Assertion-Reason Type<>	3	4	-1	12
Section 3	6	Linked Comprehension Type	4	4	-1	24
Section 4	3	Matrix-Match Type	6	0	0	18
Total	22					81

Total Marks in each part(subject) = 81
Total Marks in each part(subject) = 81 X 3 = 243
Total Marks in IIT-JEE 2007 = 2 X 243 = 486

Categorization of Questions (Easy, Medium, Difficult) for Paper-I

EASY:- Direct application of the concept required.
MEDIUM:- Multy application based problems.
DIFFICULT:- Multiple concepts and tricky problems.

Chemistry:-

Easy	6 Questions	22 Marks
Medium Difficulty	12 Questions	44 Marks
Difficult	4 Questions	15 Marks

Chemistry:-

Subject Area	Marks	%Distribution
Atomic Structure & Chemical Bonding	5X3=15	19
Metallurgy	1X3=3	4
Hydrocarbons	2X3=6	7
Basic Principles in Organic Chemistry	1X3=3	4
Dilute Solutions	1X3=3	4
Thermodynamics	1X3=3	4
P Block Elements	3X4+1X3=15
P Block Elements	3X4+1X3=15	19
Surface Chemistry	1X3=3	4
Electrochemistry	4X3=12	15
Coordination Compounds	1X6=6	7
Biomolecules / Polymers	1X3=6	7
States of Matter	1X6=6	7
	81	100

Subject Area	Marks
Physical Chemistry	42
Organic Chemistry	15
Inorganic Chemistry	24
	81

Distribution of marks across various areas - Paper-II

Chemistry:-

Subject Area	Marks	%Distribution
Atomic Structure & Chemical Bonding	1X3=3	3.7%
Metallurgy
Hydrocarbons
Basic Principles in Organic Chemistry	1X3=3	3.7%
Dilute Solutions
Thermodynamics	1X3=3	3.7%
P Block Elements	0	0
Surface Chemistry	0	0
Electrochemistry	2X4=8	9.9%
Coordination Compounds	1X3=3	3.7%
Biomolecules / Polymers	1X	3.7%
States of Matter	0	0

Qualitative analysis	1X3=3	3.7%
Aldehyde and ketone	1X3=3	3.7%
Stereo chemistry	2X3=6	7.4%
Nuclear chemistry	1X3=3	3.7%
S block elements	1X3=3
S block elements	1X3=3	3.7%
Purification and characterization of organic compounds	1X4=4	4.9%
Phenols	3X4=12	14.8%
Organic reactions	1X6=6	7.4%
Solid state	1X6=6	7.4%
Redox reaction	1X6+1X3=9	11.1%
Chemical kinetics	1X3=3	3.7%
		81	100

TOP

ANALYSIS OF JEE RESULT:-

No. of Students Appearing:-About 2. Lakh of candidates,
No. Of Serious Students :- Approx -50,000.
Clearing the Screening Paper.:-It is common among all the students to practice an enormous quantity of multiple choice questions (mcqs) throughout the year. This mcq helps a student in no way. Your first job will be to keep away from this practice. JEE Screening test demands clarity of each and every concept. Hence, from the beginning of the year, try to assimilate the theory of each and every chapter given in the JEE syllabus
The final hurdle ? Main Examination..JEE mains nowadays depends on accuracy (More than one choice, Assertion Reasoning , Matrix Matching..
This part can be prepared only through exhaustive coverage of syllabus and practice of selective very similar problems.
Books required for JEE preparation..........
Standard JEE books (contains questions similar to JEE standards ? do all the problems)
Chemistry : P. Bahadur(Physical Chemistry) , O.P.Tondon(Inorganic) and Jagdamba Singh ( Organic)
Advanced JEE books (questions are a bit higher than JEE standards - do selected problems ? take help of your mentor/teacher)
Chemistry : IIT Chemistry - Tata McGraw Hill.
For theory you can go through Carey in Organic Chemistry, and O.P.Tandon in Inorganic Chemistry.
The changing trend in JEE.....................
From the year 2002, a changing pattern of JEE can be observed. now a days nature of problem pattern is flexible.

Institutions using Extended Merit List of JEE-2008

S. No.	List of Institute	Website	Address
1.	Indian Institute of Space Science and Technology	http://www.iist.ac.in	Shri G. Madhavan Nair Secretary, DOS Antariksh Bhawan New BEL Road BANGALORE
2.	Indian Institute of Science Education and Research
(a)	Mohali	http://www.iisermohali.ac.in/	IISER Mohali MGSIPA Complex Sector-26 CHANDIGARH-160019
(b)	Pune	http://www.iiserpune.ac.in/	IISER Pune 900 NCL Innovation Park Dr. Homi Bhabha Road PUNE-411008
(c)	Kolkata	http://www.iiserkol.ac.in/	IISER Kolkata HC-VII, Sector-III Salt Lake KOLKATA-700106
(d)	Bhopal		IISER Bhopal
(e)	Thiruvananthapuram		IISER Thiruvananthapuram
3.	Rajiv Gandhi Institute of Petroleum Technology Society (RGPIT)		Dr. R.K. Suri Executive Director RGPIT C/o BPCL Northern Region Office NOIDA-201301 (U.P.)
4.	Indian Institute of Maritime Studies (Merchant Navi)	http://iims.dgshipping.com/	Indian Institute of Maritime Studies C/o Lal Bahadur Shastri College of Advanced Maritime Studies and Research Hay Bunder Road MUMBAI-400033

Stoichiometry Online Help

2008-11-23T10:27:00.001-08:00

What is Stoichiometry?

The word stoichiometry derives from two Greek words: stoicheion (meaning "element") and metron (meaning "measure"). Stoichiometry deals with calculations about the masses (sometimes volumes) of reactants and products involved in a chemical reaction. It usually determines how much of a substance is expected to react or be produced in a chemical reaction. It is a very mathematical part of chemistry, so be prepared for lots of calculator use.

Jeremias Benjaim Richter (1762-1807) was the first to describe the principles of stoichiometry. In 1792 he wrote:

"Die stöchyometrie (Stöchyometria) ist die Wissenschaft die quantitativen oder Massenverhältnisse zu messen, in welchen die chymischen Elemente gegen einander stehen." (German translated into English: Stoichiometry is the science of measuring the quantitative proportions or mass ratios in which chemical elements stand to one another.)

The key steps (in order) to doing stoichiometry:

1. Balance your equation first.

2. Convert from grams to moles using molar mass.

3. Determine the limiting reagent [if necessary] (Use mole ratios to figure out.)

4. Use ratios to find the moles of the reactant or product you need to find.

5. Convert from moles back to grams of the new substance using that substance's molar mass.

6. Calculate percent yield [if necessary] (Divide actual yield by theoretical yield X 100%)

Sample Example Problem [to show you how it's done]:

Problem: How many grams of silicon carbide are produced when 50.0 g of silicon dioxide is heated with 32.0 g of carbon?

SiO₂ (s) + C (s) à SiC (s) + CO (g) [unbalanced]

1. Balance your equation first.

SiO₂ (s) + 3C (s) à SiC (s) + 2CO (g) [balanced]

2. Convert from grams to moles using molar mass.

To get moles from grams of silicon dioxide (SiO₂): [molar mass = 60 g/mol]

50.0 g SiO₂ X ( 1 mol / 60 g ) = 0.833 mol SiO₂

To get moles from grams of carbon (C): [molar mass = 12 g/mol]

32.0 g C X ( 1 mol / 12 g ) = 2.667 mol C

3. Determine the limiting reagent [if necessary] (Use mole ratios to figure out.)

Figure out how many moles of C would need to react with 0.833 moles SiO₂:

* From your balanced equation, the ratio is 3 mol C: 1 mol SiO₂.

0.833 mol SiO₂ X ( 3 mol C / 1 mol SiO₂ ) = 2.5 mol C needed

* But you have 2.667 mol C to start with and need 2.5 mol C to react, so you have extra C and limiting reagent is SiO₂

* To calculate excess: 2.667 - 2.500 = 0.167 mol C in excess

Figure out how many moles of SiO₂ would need to react with 0.833 moles C:

* From your balanced equation, the ratio is 1 mol SiO₂ : 3 mol C.

2.667 mol C X ( 1 mol SiO₂ / 3 mol C ) = 0.889 mol SiO₂ needed

* But you have 0.833 mol SiO₂ to start with and need 0.889 mol SiO₂ to react, so you have SiO₂limiting reagent because you don't have enough SiO₂needed to react

* Compare 0.889 mol SiO₂needed vs. 0.833 mol SiO₂you started with

4. Use ratios to find the moles of the reactant or product you need to find.

Since SiO₂ is the limiting reagent, you use the moles of SiO₂if you have to calculate how many grams of silicon carbide (the product you're trying to find) are being produced. Use your mole ratios from your balanced equation:

0.833 mol SiO₂ X ( 1 mol SiC / 1 mol SiO₂ ) = 0.833 mol SiC produced

5. Convert from moles back to grams of the new substance using that substance's molar mass.

To get grams from moles of carbon (SiC): [molar mass = 40 g/mol]

0.833 mol SiC X ( 40 g / 1 mol ) = 33.33 g SiC produced

Answer to Problem: 33.33 g SiC produced = the theoretical yield

inorganic chemistry

2008-11-23T10:24:00.001-08:00

IIT Chemistry Sample Paper 1

Inorganic

An aq soln of a gas X gives the fol reactions:
1. It decolorizes an acidified soln of K₂Cr₂O₇
2. On boiling it with H₂O₂, cooling it and then adding an aq soln of BaCl₂ a ppt insoluble in dil HCl is obtained.
3. On passing H₂S a white turbidity is obtained.
Identify X and give all reactions taking place.
The gas liberated on heating a mix of 2 salts with NaOH gives a reddish brown ppt with an alk soln K₂HgI₄. The soln (aq) of the mix on treatment with BaCl₂ gives a white pt which is sparingly solution in conc HCl. On heating the mix with K₂Cr₂O₇ and conc H₂SO₄ red vap of A are produced. The aq soln of the mix gives a deep blue coloration B with pot ferricyanide soln. Identify the radicals and write balanced eqns for formation of A and B?
A black colored compd A on reaction with dil H₂SO₄ gives a gas B which on passing in a soln of an acid C gives a white turbidity D. Gas B when passed thro acidified soln of E gives a ppt F solution in dil HNO₃. After boiling this soln when an excess of ammonium hydroxide is added a blue colored compd G is formed. To this soln on addn of acetic acid and aq pot ferrocyanide a chocolate ppt H is obtained. On addn of an aq soln of E a white ppt insol in HNO₃ is obtained. Identify A to H.
A mix of 2 salts were treated as follows:
1. The mix was heated with manganese dioxide and conc H₂SO₄ when yellowish green gas was obtained.
2. The mix on heating with sod hydroxide soln gave a gas, which turned red litmus blue.
3. Its soln in water gave blue ppt with pot ferricyanide and red coloration with amm thiocyanate.
4. The mix was boiled with pot hydroxide and the liberated gas was bubbled thro an alk soln of K₂HgI₄ to give brown pt.
Identify the 2 salts. Give ionic reactions for the tests (i) to (iii).
A certain inorganic compd A on heating loses its water of crystallization. On further heating a blackish powder B and 2 oxides of S - C and D are obtained, the powder B on boiling with HCl gives a yellow soln E. When H₂S is passed thro E a white turbidity F and apple green soln G are obtained. The soln E on treatment with thiocyanate ions gives a blood red color compd H. Identify A to H.
A green colored metallic chloride A when treated with sod hydroxide and H₂O₂ gives a yellow soln due to the formation of compd B. The color of this soln changes to orange when dil H₂SO₄ is added to it. It is due to the formation of compd C. When KCl is heated along with C in presence of conc H₂SO₄ a red volatile liq D is formed. The compd C when treated with amm chloride forms compd E which decomposes on heating giving a colorless gas F water and green residue G. When Mg is burnt in the presence of F a white solid H is formed. The latter on hydrolysis forms a gas I which gives white fumes with HCl. Identify A to I giving involved eqns.
Your are given a white material which could be any of the following :
ZnO, ZnCO₃, Zn(OH)₂, ZnS, Zn(NH₃)₄Cl₂.
What tests would you perform to identify the compd? Be specific. Tell what reagents you could use and what observations you could make.
A white amorphous powder A on heating yields a non-combustible gas B and a solid C. The latter compd assumes a yellow color on heating and changes to white on cooling. C dissolves in dil acids and the resultant soln gives a white ppt on adding K[Fe(CN)₄] soln. A dissolves in dil HCl with the evolution of a gas which is identical in all respects with B. The gas B turns lime water milky which disappears on continuous passage of it. The soln of A as obtained above gives a white ppt D on addn of excess of NH₄OH and passing H₂S. Anther portion of the soln gives initially a white ppt E on addn of NaOH soln which dissolves on further addn of base. Identify A-E.
A colorless solid A on heating gives a white solid B and a gas C; B gives off reddish brown fumes on treatment with dil acids. On heating with NH₄Cl, B gives a colorless gas D and a residue E. The compd A also gives colorless gas F on heating with ammonium sulphate and white residue G. Both E and G impart yellow color to the Bunsen flame. C forms white powder with strongly heated Mg metal. The white powder forms Mg(OH)₂ with H₂O. The gas D on the other hand is observed by heated Ca which gives off ammonia on hydrolysis. Identify the substance A to G and give reactions for the changes involved.
A mix of 3 gases A, B, C is passed first into acidified dichromate solution when A is absorbed turning the soln green. The remainder of the gas is passed through excess of lime water which turns milky resulting in the absorption of B. The residual gas C is absorbed by alk pyrogallol soln. However the original mix does not turn lead acetate paper black. Identify A, B, C.

U.S. National Chemistry Olympiad

2008-11-23T10:13:00.000-08:00

U.S. National Chemistry Olympiad: 2009 Program Schedule

If you would like to participate in the U.S. National Olympiad (USNCO), refer to this schedule for important dates and deadlines.

Date/What Affects Whom Action Required
October 13, 2008

* Invitations to participate in the 2009 U.S. National Chemistry Olympiad emailed to all ACS local section chairs, chair elects and current Olympiad coordinators
* Coordinator’s handbook available online

• Local section chairs • Chair-elects • Current Olympiad Coordinators • Contact the USNCO national office for an Olympiad Participation Form.
November 21, 2008
Olympiad program package mailed to coordinators (Includes student allotment for national exam and promotional posters. Mailing labels available upon request) Coordinators • Provide content to chemistry teachers at high schools within your local section.
January 23, 2009
Participation Response Form Due! Coordinators • Submit the ACS Local Section 2009 Participation Response Form to the USNCO national office.
January 27, 2009
Deadline to order local examinations Coordinators • Order local examinations
from the ACS Division of Chemical Education Examinations Institute. • Order forms available through the USNCO national office (There is a 25% surcharge for late orders).
January 27, 2009
Mentor applications due! High school mentor applicants • Submit an Olympiad Mentor Application Form to the USNCO national office. • Review mentor guidelines and responsibilities.
February 16, 2009
Local exams mailed to local sections Coordinators
March 2-31, 2009
Chemistry Olympiad local examinations administered (Answer key for local exams will be available on April 3, 2009)

Coordinators
Students • Coordinators identify students for the National Chemistry Olympiad competition.
March 31, 2009
Lab practical sites due! Coordinators • Submit a list of all lab practical sites to the USNCO office to obtain insurance coverage.
April 6, 2009
National Exams mailed to participating local section Coordinators
April 17, 2009
Certificate Request forms due! Coordinators • Submit the 2008 Certificate Request Form to the USNCO office. (available soon)
April 23-27, 2009
U.S. National Chemistry Olympiad Exam Administered (Answer key for Part I-Multiple Choice of the exam will be available on May 8) • Students • Coordinators
April 29, 2009
National exams due for grading Important: Exams received after this date will not be graded Coordinators • Send exam answer sheets via UPS in the prepaid envelopes to the ACS National Examinations Institute.
May 4, 2009
Top 20 students announced (Coordinators for selected students will be contacted by phone. All other sections will be notified by mail) • Students • Coordinators • Coordinators inform students chosen to attend the study camp.
June 7-21, 2009
Top 20 students attend Olympiad Study Camp • Students • Mentors
June 20, 2009
U.S. team for the International Chemistry Olympiad announced • Students • Mentors
July 18-27, 2009
U.S. team competes in the International Chemistry Olympiad competition in Cambridge, England • Students • Mentors
Contact Us

For more information, please contact the U.S. National Chemistry Olympiad at:

American Chemical Society
U.S. National Chemistry Olympiad Office
1155 16th Street NW
Washington, DC 20036

Email: usnco@acs.org

Phone: (800) 227-5558 ext. 6328.

chemical kinetics

2008-11-23T10:09:00.000-08:00

Chemical Kinetics Date:
Study Questions Period:
Directions: Answer the following questions on a separate sheet of paper. Must show your work. Put
your final numerical answers in a box.
1. In the following reaction, what is the relationship between the rate at which the nitrous oxide is used up, the rate at which the oxygen is used, and the rate at which the nitrogen dioxide is produced?
2N2O(g) + 3O2(g)  4NO2(g)
2. Ammonia can be oxidized by oxygen to produce nitrogen dioxide according to the equation:
4NH3(g) + 7O2(g)  4NO2(g) + 6H2O(g)
If, in this reaction, water is formed at a rate of 36 mol L-1 min-1,
a. at what rate is the ammonia used?
b. at what rate is the oxygen used?
c. at what rate is the nitrogen dioxide formed?
3. If a reactant is used up according to a first order rate equation, and the initial concentration of the reactant is 3.2 mol L-1, what is the concentration of the reactant after two half-lives have passed, and after six half-lives have passed?
4. For each of the following rate equations, describe what would happen to the rate if the concentration of reactant A was tripled and the concentration of reactant B is halved.
a. Rate = k[A][B]
b. Rate = k[A]2[B]
c. Rate = k[A]2[B]2
d. Rate = k[A][B]3
5. The reaction of tbutyl-bromide (CH3)3CBr with water is represented by the equation:
(CH3)3CBr + H2O  (CH3)3COH + HBr
The following data were obtained from three experiments using the method of initial rates:
Initial [(CH3)3CBr]
mol L-1
Initial [H2O]
mol L-1
Initial rate
mol L-1min-1
Experiment 1
5.0 x 10-2
2.0 x 10-2
2.0 x 10-6
Experiment 2
5.0 x 10-2
4.0 x 10-2
2.0 x 10-6
Experiment 3
1.0 x 10-1
4.0 x 10-2
4.0 x 10-6
a. What is the order with respect to (CH3)3CBr?
b. What is the order with respect to H2O?
c. What is the overall order of the reaction?
d. Write the rate equation.
e. Calculate the rate constant k for the reaction.
6. At 150C the decomposition of acetaldehyde CH3CHO to methane is a first order reaction. If the rate constant for the reaction at 150C is 0.029 min-1, how long does it take a concentration of 0.050 mol L-1 of acetaldehyde to reduce to a concentration of 0.040 mol L-1?
7. The decomposition of hydrogen iodide into hydrogen and iodine is a second order reaction. The rate constant k = 0.080 L mol-1s-1. How long does it take an initial concentration of 0.050 M to decrease to half this concentration?
8. Describe some industrial uses of catalysts.
9. The gold-198 isotope has a half-life of 2.7 days. If you start with 10 mg at the beginning of the week, how much remains at the end of the week, seven days later?
10. If the rate of a reaction increases by a factor of 10 when the temperature is increased by 35C from 300K to 335K, what is the activation energy Ea for the reaction?
11. The decomposition of ozone in the upper atmosphere to dioxygen occurs by a two-step mechanism. The first step is a fast reversible step and the second is a slow reaction between an oxygen atom and an ozone molecule:
Step 1: O3(g) O2(g) + O(g) Fast, reversible, reaction
Step 2: O3(g) + O(g)  2O2(g) Slow
a. Which is the rate determining step?
b. Write the rate equation for the rate-determining step.
c. Write the rate equation for the overall reaction.
12. The rate equation for the reaction of nitrogen dioxide and carbon monoxide in the gas state to form carbon dioxide and nitric oxide is represented by the equation:
NO2(g) + CO(g)  NO(g) + CO2(g)
The following data were collected at 125C:
Initial [NO2]
mol L-1
Initial [CO]
mol L-1
Initial rate
mol L-1min-1
Experiment 1
5.0 x 10-4
1.6 x 10-2
1.7 x 10-7
Experiment 2
5.0 x 10-4
3.2 x 10-2
1.7 x 10-7
Experiment 3
1.5 x 10-3
3.2 x 10-2
1.5 x 10-6
a. What is the order with respect to NO2?
b. What is the order with respect to CO?
c. What is the overall order of the reaction?
d. Write the rate equation.
e. How do you know this is not a single step reaction?
f. Suggest a mechanism for the reaction.