Chemistry Paper-1 2021 — CSS Past Paper

FEDERAL PUBLIC SERVICE COMMISSION

COMPETITIVE EXAMINATION-2021

FOR RECRUITMENT TO POSTS IN BS-17
UNDER THE FEDERAL GOVERNMENT

CHEMISTRY, Paper-1

TIME ALLOWED: THREE HOURS
PART-I(MCQS): MAXIMUM 30 MINUTES
PART-I (MCQS) MAXIMUM MARKS = 20
PART-II MAXIMUM MARKS = 80

NOTE:

• (i) Part-II is to be attempted on the separate Answer Book.
• (ii) Attempt ONLY FOUR questions from PART-II. ALL questions carry EQUAL marks.
• (iii) All the parts (if any) of each Question must be attempted at one place instead of at different places.
• (iv) Candidate must write Q. No. in the Answer Book in accordance with Q. No. in the Q.Paper.
• (v) No Page/Space be left blank between the answers. All the blank pages of Answer Book must be crossed.
• (vi) Extra attempt of any question or any part of the attempted question will not be considered.

PART-II

Q. No. 2.

(a) Explain applications of Schrodinger wave equation to hydrogen and hydrogen like Atom. (10)

(b)

• (i) Give Molecular interpretation of entropy. (05)
• (ii) Explain factors affecting the rate of a chemical reactions. (05)

Q. No. 3.

(a) What are the uses of chelates. (07)

(b) State and explain Nomenclature of coordination complexes. (07)

(c) (Explain VBT (Valence Bond Theory) of coordination complexes in detail. (06)

Q. No. 4.

(a) Explain photoelectric effect and probability density. (10)

(b)

• (i) Explain Eigen function & Eigen value. (05)
• (ii) Derive Schrodinger wave equation for a particle in one dimensional box. (05)

Q. No. 5.

(a) Predict molecular shapes using Valence Shell Electron Pair Repulsion (VESPER) model. (10)

(b)

• (i) Explain the experimental techniques for determination of order of reaction? (05)
• (ii) Write a note on thermochemistry and calorimetry. (05)

Q. No. 6.

(a) Derive a relation for dependence of Gibbs free energy on temperature or Gibbs Helmholtz equation. (07)

(b) What is isothermal process? Explain work done in isothermal reversible expansion of an ideal gas. (07)

(c) Explain fugacity and activity. (06)

Q. No. 7.

(a) Discuss common ion effect and its industrial applications in detail. (08)

(b) Describe significance of plc■, pkb, pH. (06)

(c) Write a note on basic concepts of chemical equilibrium. (06)

Q. No. 8.

Write notes on the following:-

• (i) Debye-Huckel theory. (07)
• (ii) Nernst’s equation. (07)
• (iii) Electrochemical series. (06)

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