chemical engineering thermodynamics for chemical chemical engineering Mcqs
51. Work done in an adiabatic process between two states depends on the__________________?
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A. None of these

B. End states only

C. Rate of heat transmission

D. Initial state only

52. A chemical reaction will occur spontaneously at constant pressure and temperature, if the free energy is________________?
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A. Positive

B. Negative

C. Zero

D. None of these

53. There is a change in ______________ during the phase transition?
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A. Volume

B. Temperature

C. All a, b & c

D. Pressure

54. Pressure-enthalpy chart is useful in refrigeration. The change in internal energy of an ideal fluid used in ideal refrigeration cycle is_____________________?
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A. Negative

B. Zero

C. Positive

D. Infinity

55. A reasonably general expression for vapour-liquid phase equilibrium at low to moderate pressure is ?i yi P = Yi xifi where, ? is a vapor fugacity component, Yi is the liquid activity coefficient and fi is the fugacity of the pure component i. the Ki value (Yi = Ki xi) is therefore, in general a function of ______________________?
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A. Temperature only

B. Temperature, pressure and liquid composition xi only

C. Temperature, pressure, liquid composition xi and vapour composition yi

D. Temperature and pressure only

56. A solid is transformed into vapour without going to the liquid phase at_________________?
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A. Always

B. Boiling point

C. Below triple point

D. Triple point
57. Joule-Thomson effect i.e., a throttling process is a constant _____________ process?
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A. Entropy

B. Temperature

C. Enthalpy

D. Internal energy

58. A gas mixture of three components is brought in contact with a dispersion of an organic phase in water. The degree of freedom of the system is______________?
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A. 5

B. 4

C. 3

D. 6

59. For equilibrium process (i.e. reversible) in an isolated system __________________?
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A. ds = 0

B. ds = Constant

C. ds 0

60. A gas performs the maximum work, when it expands___________________?
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A. Adiabatically

B. Isothermally

C. Non-uniformly

D. Isobarically
61. For a reversible process involving only pressure-volume work____________________?
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A. (dA)T, v < 0

B. (dF)T, p 0

C. (dF)T, p = 0
62. Critical temperature is defined as the temperature above which a gas will____________________?
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A. Immediately liquify

B. Not liquify (barring exceptions)

C. None of these

D. Never liquify however high the pressure may be
63. The shape of T-S diagram for Carnot Cycle is a__________________?
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A. Circle

B. Rhombus

C. Rectangle

D. Trapezoid

64. A solute distributes itself between two non-miscible solvents in contact with each other in such a way that, at a constant temperature, the ratio of its concentrations in two layers is constant, irrespective of its total amount. This is_________________?
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A. The distribution law

B. None of these

C. A corollary of Henrys law

D. Followed from Margules equation

65. If two gases have same reduced temperature and reduced pressure, then they will have the same____________________?
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A. None of these

B. Mass

C. Volume

D. Critical temperature

66. Third law of thermodynamics is helpful in___________________?
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A. Prediction of the extent of a chemical reaction

B. Calculating absolute entropies of substances at different temperature

C. Evaluating entropy changes of chemical reaction

D. Both B. and C.
67. Clapeyron Equation deals with the____________________?
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A. Calculation of ?F for spontaneous phase change

B. Temperature dependence of heat of phase transition

C. Rate of change of vapour pressure with temperature

D. Effect of an inert gas on vapour pressure

68. The value of Joule-Thomson co-efficient, in case where cooling occurs after the throttling process is________________?
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A. 0

B. +ve

C. ?

D. #NAME?

69. Which of the following is not a reversible process ?
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A. Solution of NaCl in water at 50C

B. None of these

C. Atmospheric pressure vaporisation of water at 100C

D. Expansion of an ideal gas against constant pressure

70. The adiabatic throttling process of a perfect gas is one of constant enthalpy_________________?
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A. In which there is a temperature drop

B. In which there is an increase in temperature

C. Which can be performed in a pipe with a constriction

D. Which is exemplified by a non-steady flow expansion

71. When dilute aqueous solutions of two salts are mixed, the process is associated with ___________________?
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A. Decrease in temperature

B. Change in temperature which is a function of composition

C. No change in temperature

D. Increase in temperature
72. The molar excess Gibbs free energy, gE, for a binary liquid mixture at T and P is given by, (gE/RT) = A . x1. x2, where A is a constant. The corresponding equation for ln y1, where y1 is the activity co-efficient of component 1, is__________________?
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A. A . x22

B. Ax12

C. Ax2

D. Ax1

73. For an ideal gas, the enthalpy__________________?
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A. Decreases with rise in pressure

B. Is independent of pressure

C. Is a path function

D. Increases with rise in pressure

74. Which of the following is an extensive property of a system ?
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A. Pressure

B. Concentration

C. Heat capacity

D. Molal heat capacity

75. The number of degree of freedom for an Azeotropic mixture of ethanol and water in vapourliquid equilibrium, is__________________?
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A. 1

B. 2

C. 3

D. 0

76. Kopps rule is used to calculate the heat capacity of___________________?
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A. Gases

B. Solids

C. All (A), B. & (C)

D. Liquids

77. Which of the following units is not present in both the vapor compression refrigeration system and absorption refrigeration system ?
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A. Expansion valve

B. Refrigerator

C. Condenser

D. Compressor
78. Cv is given by__________________?
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A. (?V/?T)P

B. (?E/?T)V

C. (?E/?V)T

D. (?E/?P)V

79. With increase in reduced temperature, the fugacity co-efficient of a gas at constant reduced pressure___________________?
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A. Remain same

B. Decreases linearly

C. Increases

D. Decreases

80. Work done may be calculated by the expression ? p dA for _____________ processes ?
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A. Non-flow reversible

B. Adiabatic

C. Both A. and B

D. Neither A. nor B

81. Choose the condition that must be specified in order to liquify CO2 (triple point for CO2 is 57C and 5.2 atm) ?
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A. Pressure must be kept below 5.2 atm. and temperature must be kept above 57C

B. Temperature must be kept above 57C

C. Pressure must be kept below 5.2 atm

D. Pressure and temperature must be kept below 5.2 atm. and 57C respectively
82. Enthalpy changes over a constant pressure path are always zero for ______________ gas?
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A. A real

B. An easily liquefiable

C. A perfect

D. Any

83. A gas has a volume of 27.3 c.c. at 0C. Its volume at 10C (if pressure remains unchanged) will be _____________ c.c?
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A. 283

B. 273

C. 2.73

D. 28.3
84. The most important application of distribution law is in_____________________?
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A. Liquid extraction

B. Distillation

C. Drying

D. Evaporation

85. Entropy, which is a measure of the disorder of a system, is__________________?
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A. All A, B. & C

B. Zero at absolute zero temperature for a perfect crystalline substance

C. Independent of temperature

D. Independent of pressure

86. While dissolving a gas into a liquid at a constant temperature, the ratio of the concentration of the gas in the solution phase and in the gaseous phase is _______________?
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A. Infinity

B. Unity

C. Negative

D. Constant
87. Air-refrigeration cycle________________?
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A. Is the most efficient of all refrigeration cycles

B. Has very low efficiency

C. Requires relatively large quantities of air to achieve a significant amount of refrigeration

D. Both B. and C
88. The internal energy of an ideal gas is a function of its _____________ only?
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A. Molecular size

B. Volume

C. Pressure

D. Temperature
89. Efficiency of a heat engine working on Carnot cycle between two temperature levels depends upon the__________________?
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A. Two temperatures only

B. Pressure of working fluid

C. Mass of the working fluid

D. Mass and pressure both of the working fluid

90. For an isothermal reversible compression of an ideal gas_______________?
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A. Only ?E = 0

B. dQ = dE

C. Only ?H =0

D. ?E = ?H = 0
91. ____________ explains the equilibrium constant for any chemical reaction?
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A. Henrys law

B. Hesss law

C. None of these

D. Law of mass action
92. What is the ratio of adiabatic compressibility to isothermal compressibility ?
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A. > 1

B. < 1

C. >> 1

D. 1

93. Absolute zero temperature signifies the ____________________?
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A. None of these

B. Temperature of the heat reservoir to which a Carnot engine rejects no heat

C. Minimum temperature attainable

D. Temperature of the heat reservoir to which a Carnot engine rejects all the heat that is taken in

94. Pick out the wrong statement_________________?
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A. Phase rule variables are intensive properties

B. Heat and work are both state function

C. The work done by expansion of a gas in vacuum is zero

D. CP and CV are state function

95. A domestic refrigerator has a/an ____________ cooled condenser?
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A. Evaporative

B. Air

C. Gas

D. Water

96. Sublimation temperature of dry ice (solid CO2) is ____________ C?
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A. -273

B. -78

C. 5

D. 0

97. Ideal gas law is applicable at____________________?
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A. Low T, high P

B. Low T, low P

C. High T, high P

D. High T, low P
98. Pick out the wrong statement. A. The conversion for a gas phase reaction increases with decrease in pressure, if there is an increase in volume accompanying the reaction________________?
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A. The equilibrium constant of a reaction depends upon temperature only

B. rease in volume accompanying the reaction

C. With increase in temperature, the equilibrium constant increases for an exothermic reaction

D. The conversion for a gas phase reaction increases with increase in pressure, if there is a

99. Lenzs law results from the law of conservation of___________________?
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A. Mass

B. Energy

C. None of these

D. Momentum

100. During a reversible isothermal expansion of an ideal gas, the entropy change is_________________?
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A. ?

B. #NAME?

C. +ve

D. 0