61. 
(a) −1.342 𝑒 .𝑢
(b) −13.42 𝑒 .𝑢
(c) 3.652 𝑒 .𝑢
(d) 36.52 𝑒 .𝑢

Answer: (d)

62. A heat engine has efficiency 1/6. When temperature of sink is reduced by 62°𝐶, its efficiency is doubled. What is the temperature of the source?
(a) 37°𝐶
(b) 99°𝐶
(c) 62°𝐶
(d) 124°𝐶

Answer: (b)

63. The vapour pressures of pure benzene and solution of a solute in benzene at 25°𝐶 are 639.7 mm of Hg and 631.9 mm of Hg. What is the molality of the solution?
(a) 0.468 𝑚
(b) 0.312 𝑚
(c) 0.156 𝑚
(d) 0.078 𝑚

Answer: (c)

64. 
(a) −32.7 kcal
(b) 32.7 kcal
(c) −3.27 kcal
(d) 3.27 kcal

Answer: (a)

65. For a spontaneous reaction, free energy Δ𝐺, equilibrium constant 𝐾 and 𝐸 ° cell will respectively be:
(a) Negative, Greater than one and Positive
(b) Positive, Greater than one and Positive
(c) Negative, Lesser than one and Negative
(d) Positive, Lesser than one and Negative

Answer: (a)

66. Which one of the following is an extensive property?
(a) Free energy
(b) Chemical potential
(c) Refractive index
(d) Specific heat

Answer: (a)

67. Which of the following relations are correct?
(a) 2, 3 and 4
(b) 1, 2 and 3
(c) 1, 2 and 4
(d) 1, 3 and 4

Answer: (a)

68. What is the relation between K𝑝 and K𝑐 for the reaction?
(a) K𝑝< K𝑐
(b) K𝑝> K𝑐
(c) K𝑝=K𝑐
(d) K𝑝=K𝑐=0

Answer: (a)

69. An auto-thermal reactor is
(a) Suitable for a second order reaction
(b) Suitable for a reversible reaction
(c) Completely self-supporting in its thermal energy requirements
(d) Isothermal in nature

Answer: (c)

70. With decrease in temperature, the equilibrium conversion of a reversible endothermic reaction:
(a) Increases
(b) Decreases
(c) Remains unaffected
(d) Increases linearly with temperature

Answer: (b)