Q4/7N/04-13 Reg. No

St. Joseph’s College of Arts & Science (Autonomous) St. Joseph’s College Road, Cuddalore – 607001 CH408 – PHYSICAL CHEMISTRY - II

Time : 3 hrs

Max Marks :75 SECTION – A (25X1=25) Answer ALL Questions

I. Choose the correct answer 1. Which is an intensive property? a) Volume b) Free energy

c) Enthalpy

2. The unit of internal energy is a) J b) Kg

c) m2

d) Specific gravity d) dm-3

3. The entropy of defect free crystal at 0° K temperature is a) Highly positive b) Highly negative c) Zero d) Either positive or negative 4. Which is correct statement relating second law of thermodynamics? a) dS = q/T b) dS = dq.T c) dE = dq.T d) dE = dq/T 5. The standard free energy change for a process is given by a) ∆G° = ∆G + T∆S° b) ∆G° = ∆H° + T∆S° c) ∆G° = ∆S° - T∆H° d) ∆G° = ∆H° - T∆S° 6. Which will obey Raoult’s law? a) Solid solutions c) Non-ideal solutions

b) Ideal solutions c) Binary gaseous mixture

7. Which law is applicable for gases in liquid solutions? a) Distribution law b) Henry’s Law c) Hess’s law d) Third law of thermodynamics

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Q4/7N/04-13 8. Which is correct mathematical form for Distribution law? a) KD = C1+C2 b) KD = C1.C2 c) KD = C1 / C2 d) KD = C1 - C2 9. Benzene-toluene solution is an example for a) Ideal solutions b) Gases in liquid solution c) Solid solutions c) Solid in liquid solution 10. According to Henry’s law, the amount of gas dissolved in a liquid is directly proportional to a) Volume of liquid b) Pressure of gas c) Molecular weight of liquid d) Molecular weight of gas II. Fill up the blanks 11. According to first law of thermodynamics, ∆U = ________. 12. Water + ethanol is an example for _______mixture. 13. Kirchoff’s equation is ________ 14. Zinc granules reacting with dil.HCl in a beaker is an example for ________ system. 15. The depression in freezing point is directly proportional to ______ III. Match the following 16. Elevation of boiling point

– Raoult’s law

17. Entropy

– Colligative property

18. Gibbs function

– Trouton’s rule

19. pA = xA.pA°

– H – TS

20. ∆S = ∆Hv/Tb

– Measure of disorder ness

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Q4/7N/04-13 IV. Say true or False 21. Efficiency of carnot engine is always equal to one. 22. In endothermic reaction, the total enthalpy of products is lesser than that of reactants. 23. For very dilute solution, the mole fraction of solute is directly proportional to molality of the solution. 24. In exothermic reaction, the heat energy is liberated out. 25. Depression in freezing point is a colligative property

SECTION – B (5X4=20) Answer any FIVE Questions 26. a) b) 27. a) b)

State Raoult’s law. State Henry’s law. Write about Joule-Thomson effect. State zeroth law of thermodynamics

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28. a) Verify cyclic rule for one mole of ideal gas. b) Define internal energy.

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29. a) State any two limitations of first law of thermodynamics. b) Write Kelvin-Planck statement for second law of thermodynamics.

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30. a) State third law of thermodynamics. b) Define chemical potential.

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31. a) Define van’t Hoff factor. b) State any two applications of Nernst distribution law.

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Q4/7N/04-13 32. a) State first law of thermodynamics. b) Explain exact and inexact differentials.

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SECTION- C (5X6=30) Answer ALL Questions 33. b) i) Derive the relationship between Cp and Cv. (3) ii) Six moles of ideal gas expand isothermally and reversibly from a volume of 1 lit to 10 lit at 300 K, calculate the work done. (3) (or) 34. a) i) Define system, surrounding and process (3) ii) Explain state and path functions with examples (3) 35. a) i) Derive Kirchoff’s equation. (3) ii) Write about Hess’s Law. (3) (or) b) i) When naphthalene was combusted at constant volume at 298° K, the heat evolved was found to be 5138.8 kJ. Calculate the enthalpy of reaction at constant pressure. (3) ii) The enthalpy of combustion of glucose is -2816 kJ/mol at 298° K. Calculate standard enthalpy of formation of glucose. The enthalpy of formation for CO2 and H2O are -393.5 and 285.9 kJ/mol respectively. (3) 36. a) i) Derive Nernst distribution law thermodynamically. (3) ii) The boiling point of water at a pressure of 50 atm is 265oC. Compare the theoretical efficiencies of a steam engine operating between the boiling point of water at (i) 1 atm, (ii) 50 atm, assuming the temperature of the sink to be 35oC in each case. (3) (or) b) i) Find the molar elevation constant for water which evaporates at 100 °C with the absorption of 40669.2 J/mol. (3)

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Q4/7N/04-13 ii) The distribution coefficient of iodine between carbon tetrachloride and water is 85 in favour of carbon tetrachloride. Calculate the volume of carbon tetrachloride required for 95 % extraction of iodine from 100 ml of aqueous solution in a single stage extraction.

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37. a) i) Write Maxwell’s relations (3) ii) Write about the law of chemical equilibrium. (3) (or) b) i) Draw the graphical representation of Carnot cycle (3) ii) The value of Kp for the formation of carbon-di-oxide and hydrogen gases from carbon monoxide and water vapour is found to be 1.06 X 105 at 298 K. Calculate the standard free energy change. (3) 38. a) i) Derive Gibbs-Duhem-Margules equation. (3) ii) Briefly explain the principle about azeotropic distillation. (3) (or) b) i) At 303 K the vapour pressure of pure benzene and toluene are 184 and 59 torr, respectively. Calculate the total pressure of solution containing 0.4 mole fraction of benzene. (3) ii) If the total vapour pressure of a solution containing two liquids A and B is 350 torr, and their individual vapour pressures are 200 and 500 torr, respectively, calculate the mole fraction of each liquid component. (3)

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