LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

FIFTH SEMESTER – APRIL 2011

CH 5507 – PHASE EQUILIBRIA AND KINETICS

 

 

 

Date : 19-04-2011              Dept. No.                                          Max. : 100 Marks

Time : 1:00 – 4:00

 

SECTION –A

Answer ALL the questions                                                                                          (10 x 2 = 20 marks)

1. The fusion curve of ice in the phase diagram of water is inclined towards the pressure axis. Account for this phenomena.
2. State phase rule and mention the terms involved in it.
3. Define zero order reaction. Give an example.
4. Bring out the differences between order and molecularity of a reaction.
5. “Addition of a non-volatile solute lowers the vapour pressure of a solution” – Offer a theoretical explanation for this statement.
6. What do you mean by abnormal Colligative properties?
7. State the steps that are involved in the thermal decomposition of acetaldehyde.
8. Explain how ionic strength affects the rate of a reaction.
9. What is a pseudo order reaction?
10. Define the term ‘Adsorption’.

SECTION –B

Answer ANY EIGHT questions                                                                                (8 x5 = 40 MARKS)

11. Apply phase rule to sulphur system.
12. Explain phase rule to lead-silver system and discuss the desilverisation of lead from this system.
13. Define osmotic pressure. Derive a relationship between osmotic pressure and lowering of vapour-pressure.
14. If a solution containing 6g of triphenyl methane(mol.wt=244) in 1000g of benzene is cooled to 22°C below the freezing point of benzene, how much solvent will crystallize out ?

( K_f = 5.1 K kg mol^-1)

15. Derive the expression for the rate constant for the reaction 2A → products.
16. Why do the rates of reactions in general have a large temperature co-efficient?
17. The specific reaction rate of a reaction is 1 x 10^-3 min^-1 at 27°C and 2×10^-3 min^-1 at 37°C. Calculate the energy of activation of this reaction and its specific reaction rate at 47°C.
18. Explain i) consecutive reaction ii) parallel reaction with one example for each.
19. Explain the theory of absolute reaction rate and show how it is superior to other theories.

 

 

20. Derive Nernst distribution law and state its limitations.
21. State and explain the factors that affect the rate of enzyme catalysis.
22. What are Wilkinson’s catalysts? Explain its catalytic action in reactions.

 

SECTION –C

Answer any FOUR the questions                                                                               (4 x 10 = 40 MARKS)

23. Draw and explain the phase diagram of FeCl₃-H₂O system.
24. (a) How are volumetry, monometry, useful in studying the reaction kinetics. Give one example for each.

(b) Explain the mechanism of S_N1 reaction.

25. Explain Lindemann’s steady state principle. Show that the reaction is first order at high concentration and second order at low concentration. Derive the relevant expression.
26. (a) State Raoult’s law. Explain the different types of deviation from this law.

(b) Derive Clausius-Clapeyron equation and state any one of its applications.

27. Explain with a suitable diagram that lowering of vapor pressure is the cause for change in boiling point and freezing poing of a solution.
28. State the postulates of Langmuir’s adsorption equation and discuss the effects at very low and high pressures.  Derive the equation.

 

 

 

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