MCQOPTIONS
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MCQOPTIONS
This section includes 91 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
Entropy change of the reaction, H 2 O(liquid) H 2 O(gas), is termed as the enthalpy of |
| A. | solution |
| B. | vaporisation |
| C. | formation |
| D. | formation |
| Answer» C. formation | |
| 52. |
At equilibrium condition, the chemical potential of a material in different phases in contact with each other is equal. The chemical potential for a real gas (?) is given by(where, ? = standard chemical potential at unit fugacity ( f ° = 1 atm.) and the gas behaves ideally.) |
| A. | ?° + RT ln f |
| B. | ?°+ R ln f |
| C. | ?° + T ln f |
| D. | ?° + R / T ln f |
| Answer» B. ?°+ R ln f | |
| 53. |
Free energy changes for two reaction mechanism ' X ' and ' Y are respectively - 15 and - 5 units. It implies that X is |
| A. | slower than Y |
| B. | faster than Y |
| C. | three times slower than Y |
| D. | three times faster than Y |
| Answer» C. three times slower than Y | |
| 54. |
A two stage compressor is used to compress an ideal gas. The gas is cooled to the initial temperature after each stage. The intermediate pressure for the minimum total work requirement should be equal to the __________ mean of P 1 and P 2 .(where, P 1 and P 2 are initial and final pressures respectively) |
| A. | logarithmic |
| B. | arithmetic |
| C. | geometric |
| D. | harmonic |
| Answer» D. harmonic | |
| 55. |
A system undergoes a change from a given initial state to a given final state either by an irreversible process or by a reversible process, then(where, ? S 1 and ? S R are the entropy changes of the system for the irreversible and reversible processes respectively) |
| A. | ? S 1 is always < ? S R |
| B. | ? S 1 is sometimes > ? S R |
| C. | ? S 1 is always > ? S R |
| D. | ? S 1 is always = ? S R |
| Answer» D. ? S 1 is always = ? S R | |
| 56. |
In case of a reversible process (following pv n = constant), work obtained for trebling the volume ( v 1 = 1 m 3 and v 2 3 m 3 ) is max imum, when the value of ' n ' is |
| A. | 0 |
| B. | 1 |
| C. | y = 1.44 |
| D. | 1.66 |
| Answer» B. 1 | |
| 57. |
As the temperature is lowered towards the absolute zero, the value of the quantity approaches |
| A. | zero |
| B. | unity |
| C. | infinity |
| D. | none of these |
| Answer» B. unity | |
| 58. |
For water at 300°C, it has a vapour pressure 8592.7 kPa and fugacity 6738.9 kPa Under these conditions, one mole of water in liquid phase has a volume of 25.28 cm 3 and that in vapour phase in 391.1 cm 3 .Fugacity of water (in kPa) at 9000 kPa will be |
| A. | 6738.9 |
| B. | 6753.5 |
| C. | 7058.3 |
| D. | 9000 |
| Answer» C. 7058.3 | |
| 59. |
The specific heat of saturated water vapour at 100°C is |
| A. | ? |
| B. | -ve |
| C. | 0 |
| D. | +ve |
| Answer» C. 0 | |
| 60. |
The compressibility factor of a gas is given by (where, V 1 = actual volume of the gas V 2 = gas volume predicted by ideal gas law ) |
| A. | V 1 / V 2 |
| B. | V 2 / V 1 |
| C. | V 1 - V 2 |
| D. | V 1 . V 2 |
| Answer» B. V 2 / V 1 | |
| 61. |
As the temperature is lowered towards the absolute zero, the value of , then approaches |
| A. | unity |
| B. | zero |
| C. | that of the heat of reaction |
| D. | infinity |
| Answer» C. that of the heat of reaction | |
| 62. |
The value of C p & C v respectively for monoatomic gases in Kcal/kg Mole . °K are |
| A. | 5 & 3 |
| B. | 3.987 & 1.987 |
| C. | 1.987 & 0.66 |
| D. | 0.66 & 1.987 |
| Answer» B. 3.987 & 1.987 | |
| 63. |
Number of components ( C ), phase ( P ) and degrees of freedom ( F ) are related by Gibbs phase rule as |
| A. | P + F - C = 2 |
| B. | C = P - F + 2 |
| C. | F = C - P - 2 |
| D. | P = F - C - 2 |
| Answer» B. C = P - F + 2 | |
| 64. |
Internal energy of an element at 1 atm and 25° C is __________ kcal/kg.mole. |
| A. | 0 |
| B. | 273 |
| C. | 25 |
| D. | none of these |
| Answer» B. 273 | |
| 65. |
The equation, PV = nRT , is best obeyed by gases at |
| A. | low pressure & high temperature. |
| B. | high pressure & low temperature. |
| C. | low pressure & low temperature. |
| D. | none of these. |
| Answer» B. high pressure & low temperature. | |
| 66. |
Enthalpy ' H ' is defined as |
| A. | H = E - PV |
| B. | H = F - TS |
| C. | H - E = PV |
| D. | none of these |
| Answer» D. none of these | |
| 67. |
The expression, nC v ( T 2 - T 1 ), is for the __________ of an ideal gas. |
| A. | work done under adiabatic condition |
| B. | co-efficient of thermal expansion |
| C. | compressibility |
| D. | none of these |
| Answer» B. co-efficient of thermal expansion | |
| 68. |
At normal boiling point, molar entropy of vaporisation is __________ Joule/K°.mole. |
| A. | 72 |
| B. | 92 |
| C. | 142 |
| D. | 192 |
| Answer» C. 142 | |
| 69. |
If the molar heat capacities ( C p or C v ) of the reactants and products of a chemical reaction are identical, then, with the increase in temperature, the heat of reaction will |
| A. | increase |
| B. | decrease |
| C. | remain unaltered |
| D. | increase or decrease ; depends on the particular reaction |
| Answer» D. increase or decrease ; depends on the particular reaction | |
| 70. |
In the reaction, H 2 +I 2 2HI, addition of an inert gas will |
| A. | increase the partial pressure of H 2 . |
| B. | increase the partial pressure of I 2 . |
| C. | increase the total pressure and hence shift the equilibrium towards the right. |
| D. | not effect the equilibrium conditions |
| Answer» E. | |
| 71. |
In the equation, PV n = Constant, if the value of n = 0, then it represents a reversible __________ process. |
| A. | isobaric |
| B. | isothermal |
| C. | isentropic |
| D. | isometric |
| Answer» B. isothermal | |
| 72. |
Joule-Thomson effect i . e ., a throttling process is a constant __________ process. |
| A. | entropy |
| B. | temperature |
| C. | internal energy |
| D. | enthalpy |
| Answer» E. | |
| 73. |
A cyclic engine exchanges heat with two reservoirs maintained at 100 and 300°C respectively. The maximum work (in J) that can be obtained from 1000 J of heat extracted from the hot reservoir is |
| A. | 349 |
| B. | 651 |
| C. | 667 |
| D. | 1000 |
| Answer» B. 651 | |
| 74. |
In the reaction; N 2 + O 2 2NO, increasing the pressure will result in |
| A. | shifting the equilibrium towards right, |
| B. | shifting the equilibrium towards left. |
| C. | no change in equilibrium condition. |
| D. | none of these. |
| Answer» D. none of these. | |
| 75. |
Forward reaction will be favoured for the exothermic reaction, represented by CO + H 2 O CO 2 + H 2 , by |
| A. | low temperature and high pressure. |
| B. | low temperature and low pressure. |
| C. | high temperature and high pressure. |
| D. | high temperature and low pressure. |
| Answer» B. low temperature and low pressure. | |
| 76. |
A gas has a volume of 27.3 c.c. at 0°C. Its volume at 10°C (if pressure remains unchanged) will be __________ c.c. |
| A. | 2.73 |
| B. | 28.3 |
| C. | 273 |
| D. | 283 |
| Answer» C. 273 | |
| 77. |
dW and d q are not the exact differential, because q and W are |
| A. | state functions |
| B. | path functions |
| C. | intensive properties |
| D. | extensive properties |
| Answer» C. intensive properties | |
| 78. |
A solid metallic block weighing 5 kg has an initial temperature of 500°C. 40 kg of water initially at 25°C is contained in a perfectly insulated tank. The metallic block is brought into contact with water. Both of them come to equilibrium. Specific heat of block material is 0.4 kJ.kg -1 . K -1 . Ignoring the effect of expansion and contraction and also the heat capacity to tank, the total entropy change in kJ.kg -1 , K -1 is |
| A. | -1.87 |
| B. | 0 |
| C. | 1.26 |
| D. | 3.91 |
| Answer» C. 1.26 | |
| 79. |
In polytropic process ( PV n = constant), if n = 1; it means a/an __________ process. |
| A. | adiabatic |
| B. | reversible |
| C. | isothermal |
| D. | none of these |
| Answer» D. none of these | |
| 80. |
An ideal gas is taken around the cycle ABCA as shown in P - V diagram below : The work done by the gas during the cycle is equal to |
| A. | 12 P 1 V 1 |
| B. | 6 P 1 V 1 |
| C. | 3 P 1 V 1 |
| D. | P 1 V 1 |
| Answer» D. P 1 V 1 | |
| 81. |
The unity of Planck's constant ' h ' in the equation, E = hv is |
| A. | J/s |
| B. | J.S |
| C. | J/kmol |
| D. | kmol/J |
| Answer» C. J/kmol | |
| 82. |
The thermodynamic law, PV y = constant, is not applicable in case of |
| A. | ideal compression of air. |
| B. | free expansion of an ideal gas. |
| C. | adiabatic expansion of steam in a turbine. |
| D. | adiabatic compression of a perfect gas. |
| Answer» C. adiabatic expansion of steam in a turbine. | |
| 83. |
Grams of butane (C 4 H 10 ) formed by the liquefaction of 448 litres of the gas (measured at (STP) would be |
| A. | 580 |
| B. | 640 |
| C. | 1160 |
| D. | data insufficient; can't be computed |
| Answer» D. data insufficient; can't be computed | |
| 84. |
In case of steady flow compression polytropic process ( PV n = constant), the work done on air is the lowest, when |
| A. | n = y = 1.4 |
| B. | n = 0 |
| C. | n = 1 |
| D. | n = 1.66 |
| Answer» D. n = 1.66 | |
| 85. |
The four properties of a system viz . P , V , T , S are related by __________ equation. |
| A. | Gibbs-Duhem |
| B. | Gibbs-Helmholtz |
| C. | Maxwell's |
| D. | none of these |
| Answer» D. none of these | |
| 86. |
A closed system is cooled reversibly from 100°C to 50°C. If no work is done on the system |
| A. | its internal energy ( U ) decreases and its entropy ( S ) increases. |
| B. | U and S both decreases |
| C. | U decreases but S is constant. |
| D. | U is constant but S decreases. |
| Answer» C. U decreases but S is constant. | |
| 87. |
When pressure is applied on the system, ice water, then |
| A. | equilibrium can not be established. |
| B. | more ice will be formed. |
| C. | more water will be formed. |
| D. | evaporation of water will take place. |
| Answer» D. evaporation of water will take place. | |
| 88. |
The expression, , gives the free energy change |
| A. | with pressure changes at constant temperature. |
| B. | under reversible isothermal volume change. |
| C. | during heating of an ideal gas. |
| D. | during cooling of an ideal gas. |
| Answer» B. under reversible isothermal volume change. | |
| 89. |
Water on heating from 1 to 4°C |
| A. | contracts |
| B. | expands |
| C. | has same volume |
| D. | may contract or expand |
| Answer» B. expands | |
| 90. |
Pick out the wrong statement pertaining to the decomposition of PCl 5 represented by, PCl 5 PCl 3 + Cl 2 .Degree of dissociation of PCl 5 will |
| A. | decrease on addition of Cl 2 . |
| B. | increase on addition of an inert gas at constant pressure. |
| C. | decrease on increasing the pressure of the system. |
| D. | none of these |
| Answer» E. | |
| 91. |
Keeping the pressure constant, to double the volume of a given mass of an ideal gas at 27°C, the temperature should be raised to __________ °C. |
| A. | 270 |
| B. | 327 |
| C. | 300 |
| D. | 540 |
| Answer» C. 300 | |