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CSS past paper
CSS Chemistry Paper I Past Paper 2019
CSS Chemistry Paper I 2019 carries 100 marks over 3 hours. It has 7 questions.
- Marks
- 100
- Time
- 3 hours
- Questions
- 7
How to attempt: Attempt ONLY FOUR questions from PART-II. ALL questions carry EQUAL marks.
Questions
Question 1 (Part I) is the paper's MCQs, which are not reproduced here.
- Q. 2(20)
- (a)Describe the assumption of Bohr’s atomic model. Based on Bohr’s calculation, establish the energy expression of the rotation of electrons in Hydrogen like atomic species.(8)
- (b)Derive de-Broglie’s equation for the dual nature of matter. Apply this equation for microscopic and macroscopic properties of substances.(6)
- (c)What are the postulates of Quantum Mechanics?(6)
- Q. 3(20)
- (a)What is Third law of thermodynamics? How it is used to determine the entropies of substance.(7)
- (b)Discuss the isothermal expansion of a gas and derive the equation for the work done due to expansion of a gas.(7)
- (c)Explain the law of corresponding states.(6)
- Q. 4(20)
- (a)Deduce the rate expression for 2nd order reaction where both the concentration terms are same. What is the half-life period for the 2nd order reaction?(10)
- (b)What is activation energy? How it can be determined?(5)
- (c)Write a note on Transition state theory of reaction rates.(5)
- Q. 5(20)
- (a)Develop a relation among phase, component and degree of Freedom. Draw a complete diagram for water system.(10)
- (b)What is catalysis? Differentiate between positive and negative catalysis.(6)
- (c)What is stoichiometry? Explain it with help of examples.(4)
- Q. 6(20)
- (a)State and explain Lowry-Bronsted theory and Lewis theory of acids and bases. In what way Lewis theory differs from Bronsted theory.(8)
- (b)Explain with the help of examples why pH of a buffer solution does not change significantly on small addition of acids and bases.(6)
- (c)What are indicators? How a suitable indicator can be chosen? Discuss.(6)
- Q. 7(20)
- (a)Give an account of phenomena of isomerism in co-ordination compound with suitable example.(8)
- (b)Describe the extraction of thorium from mozite sand.(6)
- (c)Compare the properties of lanthanides and actinides?(6)
- Q. 8(20)
- (a)Explain Kohlrausch’s Law? Give its applications.(7)
- (b)What is meant by transport number of ions? Give different methods for determination of transport number.(7)
- (c)What is specific conductance? How it can be determined by using Wheatstone bridge?(6)
- Part-II is to be attempted on the separate Answer Book.
- Attempt ONLY FOUR questions from PART-II. ALL questions carry EQUAL marks.
- All the parts (if any) of each Question must be attempted at one place instead of at different places.
- Write Q. No. in the Answer Book in accordance with Q. No. in the Q.Paper.
- No Page/Space be left blank between the answers. All the blank pages of Answer Book must be crossed.
- Extra attempt of any question or any part of the question will not be considered.
- Use of calculator is allowed.