chemical engineering thermodynamics for chemical chemical engineering Mcqs
151. Third law of thermodynamics is concerned with the__________________?
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A. Direction of energy transfer

B. Value of absolute entropy

C. Energy transfer

D. None of these

152. Pick out the wrong statement pertaining to the decomposition of PCl5 represented by, PCl5 ? PCl3 + Cl2.Degree of dissociation of PCl5 will_________________?
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A. Decrease on increasing the pressure of the system

B. None of these

C. Decrease on addition of Cl2

D. Increase on addition of an inert gas at constant pressure

153. A system in which there is exchange of energy but not of mass, is called a/an ____________ system?
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A. Open

B. Isolated

C. Closed

D. Insulated

154. Degree of freedom of the system ice-water-vapour will be ________________?
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A. 1

B. 0

C. 3

D. 2

155. The efficiency of an Otto engine compared to that of a diesel engine, for the same compression ratio will be _______________?
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A. Same

B. Data insufficient to predict

C. Less

D. More
156. The amount of heat required to decompose a compound into its elements is _____________ the heat of formation of that compound from its elements?
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A. Same as

B. Less than

C. Not related to

D. More than

157. Which of the following processes cannot be made reversible even under ideal condition of operation ?
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A. Free expansion of a gas

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

C. Compression of air in a compressor

D. Expansion of steam in a turbine

158. Which of the following identities can be most easily used to verify steam table data for superheated steam ?
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A. (?T/?V)S = (?p/?S)V

B. (?T/?P)S = (?V/?S)P

C. (?V/?T)P = -(?S/?P)T

D. (?P/?T)V = (?S/?V)T

159. At normal boiling point, molar entropy of vaporisation is _____________ Joule/K.mole?
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A. 192

B. 72

C. 92

D. 142

160. Gibbs free energy at constant pressure and temperature under equilibrium conditions is___________________?
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A. Maximum

B. Minimum

C. 0

D. ?

161. The first law of thermodynamics is a statement of conservation of_____________________?
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A. Energy

B. Heat

C. Momentum

D. Work

162. During a reversible isothermal expansion of an ideal gas, the entropy change is___________________?
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A. 0

B. #NAME?

C. ?

D. +ve
163. In a working refrigerator, the value of COP is always__________________?
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A. 0

B. < 0

C. < 1

D. > 1
164. The necessary and sufficient condition for equilibrium between two phases is_________________?
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A. The temperature of each phase should be same

B. The pressure should be same in the two phases

C. The concentration of each component should be same in the two phases

D. The chemical potential of each component should be same in the two phases
165. Degrees of freedom at triple point will be______________?
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A. 0

B. 2

C. 3

D. 1

166. Out of the following refrigeration cycles, which one has maximum COP ?
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A. Ordinary vapor compression cycle

B. Vapor compression with a reversible expansion engine

C. Air cycle

D. Carnot cycle
167. All gases during throttling process at atmospheric temperature and pressure show a cooling effect except__________________?
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A. H2

B. O2

C. N2

D. CO2

168. The efficiency of a Carnot heat engine operating between absolute temperatures T1 and T2 (when, T1 > T2) is given by (T1 T2)/T1. The co-efficient of performance (C.O.P.) of a Carnot heat pump operating between T1 and T2 is given by__________________?
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A. T2/(T1-T2)

B. T1/T2

C. T2/R1

D. T1/(T1-T2)
169. In an ideal gas mixture, fugacity of a species is equal to its___________________?
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A. Chemical potential

B. None of these

C. Partial pressure

D. Vapor pressure

170. 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, ? S1 and ? SR are the entropy changes of the system for the irreversible and reversible processes respectively) ?
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A. ? S1 is always ? SR

B. ? S1 is always > ? SR

C. ? S1 is always = ? SR

171. In a reversible process__________________?
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A. dE dW = Tds

B. Tds dW + dE >0

C. Tds = dE + dW

D. dW dE = Tds

172. An isentropic process is carried out at constant____________________?
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A. Volume

B. Pressure

C. Temperature

D. All (A), B. and (C)

173. In which of the following reaction equilibrium, the value of equilibrium constant Kp will be more than is Kc ?
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A. N2O4 ? 2NO2

B. None of these

C. 2HI ? H2 + I2

D. 2SO2 + O2 ? 2SO3

174. Joule-Thomson Co-efficient at any point on the inversion curve is___________________?
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A. #NAME?

B. #NAME?

C. 0

D. ?

175. Fugacity of a component in an ideal gas mixture is equal to the partial pressure of that component in the mixture. The fugacity of each component in a stable homogeneous solution at constant pressure and temperature ____________ as its mole fraction increases?
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A. Remain constant

B. Increases

C. Decreases exponentially

D. Decreases

176. _____________ law of thermodynamics ascertains the direction of a particular spontaneous process?
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A. Zeroth

B. Third

C. First

D. Second
177. Which of the following is not a unit of the equilibrium constant Kp? (where, ?x = number of moles of products number of moles of reactants) ?
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A. (atm)?x, when ?x is negative

B. Dimensionless, when ?x = 0

C. (atm)?x, when ?x is positive

D. (atm)?x2, when ?x > 0
178. Helmholtz free energy A. is defined as____________________?
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A. A = H TS

B. A = H + TS

C. A = E TS

D. None of these

179. As the temperature is lowered towards the absolute zero, the value of ?(?F)/?T, then approaches_______________________?
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A. Unity

B. That of the heat of reaction

C. Zero

D. Infinity

180. A change in state involving a decrease in entropy can be spontaneous, only if ____________________?
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A. It is exothermic

B. It takes place at constant volume

C. It takes place isothermally

D. It is isenthalpic

181. The work done in isothermal compression compared to that in adiabatic compression will be__________________?
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A. More

B. Same

C. More or less depending upon the extent of work done

D. Less

182. Entropy of a substance remains constant during a/an ____________ change?
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A. None of these

B. Reversible isothermal

C. Irreversible isothermal

D. Reversible adiabatic
183. The co-efficient of performance (COP) of a refrigerating system, which is its index of performance, is defined as the ratio of useful refrigeration to the net work. The units of _____________ and COP are the same?
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A. Work

B. Temperature

C. Kinematic viscosity

D. None of these
184. Which of the following has the least thermal efficiency ?
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A. Otto engine

B. Diesel engine

C. Steam engine

D. Carnot engine

185. As the temperature is lowered towards the absolute zero, the value of the quantity (??F/?T) approaches________________?
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A. Zero

B. Unity

C. Infinity

D. None of these

186. The kinetic energy of gas molecule is zero at_____________________?
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A. 0C

B. 273C

C. -273C

D. 100C

187. 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.) ?
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A. ?+ R ln f

B. ? + R/T ln f

C. ? + T ln f

D. ? + RT ln f
188. The equation DU = Tds PdV is applicable to infinitesimal changes occuring in_________________?
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A. An open system of constant composition

B. A closed system with changes in composition

C. An open system with changes in composition

D. A closed system of constant composition

189. Linde gas liquefaction process employs cooling ____________________?
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A. None of these

B. At constant pressure

C. By expansion in an engine

D. By throttling
190. For a constant volume process_________________?
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A. dW = pdV

B. dQ = dE + pdV

C. dE = CvdT

D. dE = CpdT

191. In any spontaneous process, the ______________ free energy decreases ?
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A. Helmholtz

B. Gibbs

C. Both A. & B.

D. Neither A. nor B.

192. The expression for entropy change given by, ?S = nR ln (P2/P1), holds good for___________________?
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A. Reversible isothermal volume change

B. Cooling of a real gas

C. Heating of an ideal gas

D. Expansion of a real gas

193. Troutons ratio is given by (where ?b, = molal heat of vaporisation of a substance at its normal boiling point, kcal/kmol Tb = normal boiling point, K) ___________________?
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A. ?(Tb/?b)

B. ?(?b/Tb)

C. Tb/?b

D. ?b/Tb
194. Which of the following behaves most closely like an ideal gas ?
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A. He

B. H2

C. O2

D. N2

195. The standard state of a gas (at a given temperature) is the state in which fugacity is equal to__________________?
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A. Unity

B. Activity

C. Both A. & B

D. Neither A. nor B

196. Which of the following is true for Virial equation of state ?
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A. For some gases, Virial equations and ideal gas equations are the same

B. Virial co-efficients are function of temperature only

C. Virial co-efficients B represents three body interactions

D. Virial co-efficients are universal constants

197. What happens in a reversible adiabatic compression ?
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A. Temperature is constant

B. Cooling occurs

C. Pressure is constant

D. Heating occurs
198. (?E/?T)V is the mathematical expression for____________________?
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A. None of these

B. Free energy change

C. CV

D. Enthalpy change

199. In case of a close thermodynamic system, there is ______________ across the boundaries?
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A. No heat and mass transfer

B. Mass and energy transfer

C. No mass transfer but heat transfer

D. None of these

200. An irreversible process____________________?
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A. Yields the maximum amount of work

B. Is an idealised visualisation of behaviour of a system

C. Is the analog of linear frictionless motion in machines

D. Yields an amount of work less than that of a reversible process