FEDERAL PUBLIC SERVICE COMMISSION

COMPETITIVE EXAMINATION-2019 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.2.

• (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) (20)

Q.3.

• (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) (20)

Q.4.

• (a Deduce the rate expression for 2″ 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) (20)

Q.5.

• (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) (20)

Q.6.

• (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) (20)

Q.7.

• (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) (20)

Q.8.

• (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) (20)

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