CSS Chemistry Past Paper 2020

Instructions specific to this paper

• Attempt ONLY FOUR questions from PART-II. ALL questions carry EQUAL marks.
• Use of calculator is allowed.
• Explain Heisenberg’s uncertainty principle. (05)
• Discuss Born’s interpretation of wave function. (05) (10) (20)
• What is Hydrogen bonding. Explain. (05)

Questions

1. Q. 220 marks

   (a) Write two equations of state for real gases and compare them high lighting their (10) important features. (b) (i) Explain Heisenberg’s uncertainty principle. (05) (ii) Discuss Born’s interpretation of wave function. (05) (10)

2. Q. 320 marks

   (a) Explain the Kohlrausch law. Why do the real solution should deviate from the (10) law? (b) Compare Langmuir’s and Freundlich’s adsorption isotherms. (10)

3. Q. 420 marks

   (a) Explain the Arrhenius equation. Also high light its applications and limitations. (10) (b) Explain various acid-base theories. What are hard and soft acids and bases? (10)

4. Q. 510 marks

   (a) Make a comparison of column chromatography and thin layer chromatography (TLC) by highlighting merits and demerits of the both. (b) Explain Werner’s theory of coordination complexes. Give examples from (10) (20) d-block transition metals.

5. Q. 620 marks

   (a) Give a comprehensive classification of various chromatographic techniques. (10) Also mention potential application of each. (b) (i) What is Hydrogen bonding. Explain. (05) (ii) Describe Hybidization in p-block elements. (05) (10)

6. Q. 720 marks

   (a) Explain crystal Field Theory (CFT) for d-block elements. (10) (b) Write an extensive essay on types of chemical bonding giving examples. (10)

7. Q. 820 marks

   Write short notes on the following: (5 each) (i) Liquid junction potential (ii) Potentiometry (iii) Collision theory of Chemical reactions. (iv) Transition state theory.

Standard FPSC instructions

Printed on this and every CSS paper.

• Part-II is to be attempted on the separate Answer Book.
• 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 question paper.
• No page/space be left blank between the answers. All the blank pages of the Answer Book must be crossed.
• Extra attempt of any question or any part of the attempted question will not be considered.