Download Equilibrium and Kinetics

B.Sc Chemistry (Core)
CH6B03 – Equilibrium and Kinetics
Model Question Paper
Total Marks: 60
Time- 3 hours
Part A
Answer all the eight questions. Each question carries one mark
1. Write down the Arrhenius equation relating the rate constant and the activation energy. Explain
the terms used in the equation.
2. What is meant by the term reaction order as used in chemical kinetics?
3. Determine the number of components in a mixture of CaCO3(s), CaO(s) and CO2 (g) when
CaO and CO2 in the system are formed exclusively by the decomposition of CaCO3.
4. Give the reduced phase rule.
5. Partial molar free energy is designated as ……………
6. At equilibrium, the value of ΔG is ……………
7. State the third law of thermodynamics.
8. Give one example of a state function.
8x1=8
Part B
Answer any six questions. Each question carries two marks
9. The half-life of a first order reaction is 24 days. (i) Calculate the rate constant for the reaction (ii)
The time taken for 75% of the reactant to decay.
10. Derive an expression for the variation of reactant concentration with respect to time for a
reaction which exhibits zero order kinetics. How can this expression be used graphically to evaluate
the rate constant?
11. Sketch and label the phase diagram of Sulphur system.
12. Differentiate between the terms triple point and eutectic point. .
13. What is Joule Thomson Inversion Temperature?
14. What are extensive and intensive properties? Give one example for each.
15. Calculate the efficiency of a heat engine operating between 400 K and 300 K.
16. What is activity coefficient? Mention its physical significance.
17. Give the integrated van’t Hoff’s equation.
18. Calculate Kc for the reaction 2SO3 (g)
2SO2 (g) + O2 (g), for which Kp = 3.5x10-23 at
270C.
6 x 2 = 12
Part C
Answer any four questions. Each question carries four marks
19. Illustrate the phase diagram for a three component system.
20. Explain how a catalyst serves to enhance the rate of a chemical reaction. What is the difference
between heterogeneous and homogeneous catalysis?
21. Discuss the criteria for spontaneity in terms of thermodynamic functions G, S, H, U and A. 22.
Establish relation between equilibrium constants (i) Kp and Kc (ii) Kp and Kx
23. Why Cp is greater than Cv for a gas. Show that Cp – Cv = nR for an ideal gas.
24. ‘Entropy of the universe is increasing.’ Explain this statement.
4x 4 = 16
Part D
Answer any two questions. Each question carries twelve marks
25. Describe how phase diagram for a compound with congruent melting point is different from that
of a compound with incongruent melting point with suitable examples.
26. Describe the collision theory of gas phase chemical reactions and compare the theoretical
expression for the rate constant derived using this theory with the empirical Arrhenius equation.
27. Derive Claypeyron-Clausius equation. Discuss its applications.
28.
1. Write short notes on
a. Reversible isothermal processes
b. Adiabatic expansion
c. Joule – Thomson Coefficient and its significance
d. Entropy and spontaneity
e. Gibbs Duhem Equation
(5 x2)
2. Five moles of ideal gas are expanded from 10 dm3 to 20 dm3, isothermally at 300 K.
Calculate the entropy change of the system.
2 marks
2 x12 = 24