Q 1. Q 2. Q 3. Q 4. Q 5. Q 6. Q 7. The incorrect option in the following table is: H S Nature of reaction (a) negative positive spontaneous at all temperatures (b) positive negative non-spontaneous regardless of temperatures (c) positive positive spontaneous at low temperatures (d) negative negative spontaneous at low temperatures roperty of a system which is independent of the amount but depends upon the nature of the substance present is called (a) extensive property (b) intensive property (c) thermal property (d) physical property The temperature of 5 ml of a strong acid increases by 5 C when 5 ml of strong base is added to it If 10 ml of each is mixed and complete neutralisation takes place then rise in temperature will be: (a) 20 C (b) 10C (c) 5 C (d) 2 C Identify the intensive quantities from the following: (a) enthalpy (b) volume (c) refractive index (d) none of these At 300 K, the reaction with which of the following values of thermodynamics parameters occur non-spontaneously: (a) G = - 400 kj per mol (b) H = 200 kj per mol; S = -4 J per mol per kelvin (c) H = - 200 kj per mol; S = 4 J per mol per kelvin (d) H = 200 J per mol; S= 40 J per mol per kelvin In the reaction 2H 2 (g) + O 2 (g) 2H 2 O(l), H = -a kj (a) a kj is the heat of formation of H 2 O (b)a/2 kj is the heat of reaction (c) a kj is the heat of combustion of H 2 (d) a/2 kj is the heat of formation of H 2 O Variation of heat of reaction with temperature is given by Kirchhoff s equation. Which of the following is not the equation for Kirchhoff? (a) H 2 = H 1 + C y (T 2 -T 1 ) (b) dh = TdS + Vd H 2 H1 dh (c) C p (d) C p T T Q 8. When a solid melts, there will be: (a) a decrease in enthalpy (c) a decrease in internal energy (b) a decrease in free energy (d) no change in enthalpy Q 9. Enthalpy change does not equals internal energy change when: (a) all the reactants and products are in solution (b) reaction is carried out in a dosed vessel (c) number of moles of gaseous reactants and that of products is equal (d) reaction is carried out at constant pressure
Q 10. When the gas is ideal and the process is isothermal: (a) 1 V 1 2 V 2 (b) U 1 = U 2 (c) H 1 H 2 (d) W = 0 Q 11. Which of the following conditions will apply conversion of ice into water? H S G (a) negative negative negative at low T (b) negative negative positive at low T (c) positive positive positive at low T (d) positive positive negative at low T Q 12. The standard molar enthalpy of CO 2 is equal to: (a) the standard molar enthalpy of combustion of gaseous carbon (b) the standard molar enthalpy of combustion of carbon (graphite) (c) the sum of standard molar enthalpies of formation of CO and O 2 (d) none of the above Q 13. The enthalpy change for the process, C(graphite) C(g) is called: (a) heat of vaporisation (b) heat of allotropic change (c) heat of atomisation (d) all of these Q 14. Which of the following statement is correct? (a) The work done on the system by the surroundings is negative (b) The work done by the system on the surroundings is positive (c) The heat absorbed by the system from the surroundings is positive (d) The heat absorbed by the Surroundings from the system is positive Q 15. Choose the correct relation: (a) G = H + TS (b) U = H + V (c) U = q + W 2 (d) qv = q p - n g RT Q 16. 50 ml of water takes 5 minutes to evaporate from a vessel on a heater connected to an electric source which delivers 400 W. The enthalpy of vaporisation of water is : (a) 40.3 kj per mol (b) 43.2 kj per mol (c) 16.7 kj per mol (d) 180.4 kj per mol Q 17. The standard molar heat of formation of ethane, CO 2 and H 2 O(l) are respectively - 21.1, - 94.1, and -68.3 kcal. The standard molar heat of combustion of ethane will be: (a) -372 kcal (b) 162 kcal (c) -240 kcal (d) 183.5 kcal Q 18. An adiabatic process is one in which : (a) all energy is transferred as heat (b) du dw (c) the temperature of a gas decreases in a reversible adiabatic expansion. (d) pressure remains constant Q 19. The criteria for non-spontaneity of a process is : (a) (dg) T p < 0 (b) (du)s V < 0 (c) (ds) U v < 0 (4) (dh) S, < 0
Q 20. The expression representing Gibbs-Helmholtz equation is : G G H (a) G H T 2 (b) 2 T T T G / T (1/ T) H (c) Q 21. Given (1) S + O 2 SO 2, H = -298 2 kj (2) SO 2 + 2 1 O2 SO 3 H = - 98.7 kj (3) SO 3 + H 2 O H 2 SO 4, H = - 1302 kj (4) H 2 + 2 1 O2 H 2 O, H = - 287.3 kj G / (d) T T H Then the enthalpy of formation of H 2 SO 4 at 298 K will be : (a) 814.4 kj (b) +320.5 kj (c) 650.3 kj (d) -933.7 kj Q 22. Which of tie following statements Is incorrect? (a) The entropy of an isolated system increases in an irreversible process (b) The entropy of an isolated system remains unchanged in a reversible process (c) S system as well as S surrounding are negative quantities (d) Entropy can never decrease Q 23. The second law of thermodynamics states that: (a) entropy of the universe is decreasing continuously (b) energy can neither be created nor destroyed (c) all spontaneous precesses are thermodynamically irreversible (d) at absolute zero free energy is zero Q 24. Choose the correct relation : (a) G = H + nrt G (c) G = H + T T (b) G = H + TS (d) none of the above Q 25. Calculate the work done in joules when 2.5 mole of H 2 O vaporises at 1 atm. and 298 K. Assume that volume of liquid H 2 O is negligible in comparison to vapour. (given 1 L atom = 101.3 J, R = 0.0821 L atm per mol per kelvin) (a) 6190 kj (b) 6.19 kj (c) 61.1 kj (d) 5.66 kj Q 26. Choose the intensive property of the following: (a) heat capacity (b) internal energy (c) temperature (d) none of these Q 27. The incorrect statement among the following is: (a) when G = 0 the system is at equilibrium
(b) when G > 0 the process will be spontaneous (c) when G is negative the process will be exergonic (d) when AG is positive the process will be endergonic Q 28. A scientist needs a refrigeration machine to maintain a chemical reaction at a temperature of -13C How much work not be performed on the system during each cycle of its operation if 3000 J of heat is to be withdrawn from the -13 C reservoir and discharged to the room at +27 C in each cycle (Assume machine operates at 100% of its theoretical efficiency) (a) 65000J (b) 3000J (c) 154J (d) 133J Q 29. Which of the following are thermodynamically stable? (a) C (diamond) (b) C (graphite) (c) 4 (red) (d) All are equally stable Q 30. The incorrect statement among the following is : (a) absolute value of Internal energy cannot be determined (b) absolute value of heat content can be determined (c) absolute value of entropy can be determined (d) all the three i.e. E, H and S are extensive properties Q 31. Regarding an isothermal irreversible expansion of an ideal gas, which of the following is correct? (a) U = infinity (b)-wq = nrt 1 2 1 (c) H 0 (d) All the above are correct Q 32. The table given below lists the bond dissociation energy (E diss ) for single covalent bonds formed between C-atom and atoms l,m,n, and o: Bond E diss (kcal per mol) C - l C - m C - n C - o 240 382 276 486 The smallest atom will be that of : (a) l (b) m (c) n (d) o Q 33. The exothermic reaction among the following is: (a) decomposition of water (b) conversion of graphite to diamond (c) combustion of CH 4 (d) dehydrogenation C 2 H 6 C 2 H 4 Q 34. The differential form of thermodynamic energies U, H and G cannot be represented by : (a) du = Tds - dv (b) dh = Tds + Vdp (c) dg = - SdT + Vdp (d) dh = T + Vdp
Q 35. The enthalpy of dissolution of. BaCl 2 (s) and BaCl 2 are - 20.6 and 8.8 kj per mol respectively. The enthalpy of hydration for, BaCl 2 + 2H 2 O BaCl 2. 2H 2 O(s) is: (a) 29.4 kj (b) - 29.4 kj (c) -11.8 kj (d) 38.2 kj Answers 1. c 2. b 3. c 4. c 5. b 6. d 7. b 8. b 9. d 10. b 11. c 12. b 13. b 14. c 15. d 16. b 17. a 18. c 19. c 20. c 21 a 22. c 23. c 24. c 25. b 26. c 27. b 28 b 29. b 30. b 31. b 32. d 33. c 34. d 35. b