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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI 600 034
M.Sc.DEGREE EXAMINATION CHEMISTRY
THIRDSEMESTER APRIL 2018
16PCH3MC02/CH3814 THERMODYNAMICS AND CHEMICAL KINETICS
Date: 26-04-2018 Dept. No. Max. 100 Marks
Time: 09:00-12:00
Part-A
Answer ALL questions. (10 × 20)
1. Define Chemical potential.
2. Show that n1,n2, /T2
3. What are coupled and uncoupled reactions?
4. State Prigogine's principle of minimum entropy production.
5. Obtain the relationship between internal energy and partition function.
6. The entropy of activated complex increases for the reaction between two oppositely charged ions in
solution Justify.
7. What is the effect of temperature on the rate of enzymatic reactions?
8. Draw the potential energy diagram of a catalysed reaction forming van't Hoff intermediate.
9. The rate constant for the reaction, OH- → H2O is 1.3 × 1011 dm3 mol-1 s-1. Calculate the half-life
for the neutralisation process if 0.1 M.
10. How are chain reactions classified based on the number of radicals produced in propagation step?
Part-B
Answer any EIGHT questions. × 40)
11. Explain the three important uses of Ellingham diagram with suitable examples.
12. Obtain the phenomenological equations and their cross coefficients for streaming potential and
electro-osmosis.
13. Calculate the vibrational partition function for nitrogen gas at 300 if the vibration
frequency is 2360 x 102 m-1.
14. How does a concept of irreversible thermodynamics apply to biological process?
15. Discuss the Einstein theory for specific heat capacity of solids.
16. Derive the Sackur-Tetrode equation for a monoatomic gas.
17a. Calculate the number of collisions per second in one cubic centimetre of iodinecontaining 1.04 × 19
molecules at 300 K. (Given: Collision diameter, σ 4.6 Å and MIodine 254 g mol-1).
b. Differentiate time and true order of a reaction with the relevant graphs.
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18. Explain the effect of added salt on the rates of ionic reactions in solution.
19. Discuss the kinetics of free radical polymerization reactions.
20. Describe any one mechanism for a bimolecular surface reaction with an example.
21. Explain the kinetics of hydrogen-bromine reaction.
22. Compare the rate constant expressions obtained by TST and collision theory for the reaction between
two atoms
Part-C
Answer any FOUR questions. × 10= 40)
23a. Sketch the phase diagram and arrive at the degrees of freedom for all the regions of a ternary system leading to the formation of double salts.
b. Discuss any two methods of determining the fugacity of a real gas.
24a. State Peltier effect and obtain their phenomenological equations and coefficient.
b. Explain Onsager theory in the light of phenomenological reciprocal relationship.
25a. What are Bosons? Obtain the most probable distribution of indistinguishable particles using Bose-Einstein statistics.
b. Calculate the translational partition function of NO molecule at 500 K in a volume of 100 m3 assuming the gas to behave ideally.
26a. Explain the kinetics of atom and radical combination reactions.
b. Find the value of Δ≠Hº for a bimolecular reaction having 115 kJ mol-1 of activation energy.
27a. Explain the principle of flash photolysis to study the kinetics of fast reactions.
b. Explain the kinetics of consecutive reactions with a relevant graph.
28a. Discuss the effect of substrate concentration on enzymatic reaction.
b. The rate of an enzymatic reaction is 2.48×10-4 mol L-1 min-1 and is decreased by a factor of 2.4 if a
competitive inhibitor is present. Calculate the degree of inhibition.