chemical engineering thermodynamics for chemical chemical engineering Mcqs
201. As the entropy of the universe is increasing, day by day, the work producing capacity of a heat engine is_________________?
comments icon0

A. Increasing

B. Not changed

C. Data sufficient, cant be predicted

D. Decreasing
202. The equation, Cp Cv = R, is true for _______________ gas?
comments icon0

A. No

B. Any real

C. Only ideal

D. Both B. and C.

203. Entropy is a measure of the _____________ of a system?
comments icon0
A. Disorder

B. Orderly behaviour

C. Temperature changes only

D. None of these

204. Generation of heat by friction is an example of a/an ________________ change?
comments icon0
A. Irreversible

B. Adiabatic

C. Isothermal

D. Reversible

205. Vapour which is at a pressure smaller than the saturation pressure for the temperature involved is called a _____________ vapour?
comments icon0
A. Superheated

B. None of these

C. Desuperheated

D. Non-condensable

206. What is the degree of freedom for two miscible (non-reacting) substances in vapor-liquid equilibrium forming an azeotrope ?
comments icon0

A. 0

B. 1

C. 2

D. 3

207. PV? = Constant (where, ? = Cp/Cv) is valid for a/an ______________ process?
comments icon0

A. Isobaric

B. Isothermal

C. Adiabatic

D. Isentropic

208. First law of thermodynamics deals with the ___________________?
comments icon0

A. Irreversible processes only

B. Direction of energy transfer

C. Reversible processes only

D. None of these

209. The variation of heat of reaction with temperature at constant pressure is given by the ____________ law?
comments icon0

A. None of these

B. Antoines

C. Kelvins

D. Kirchoffs
210. Out of the following refrigeration cycles, which one has the minimum COP (Co-efficient of performance) ?
comments icon0

A. Carnot cycle

B. Ordinary vapour compression cycle

C. Vapour compression with a reversible expansion engine

D. Air cycle
211. The ratio of equilibrium constants (Kp2/Kp1) at two different temperatures is given by____________________?
comments icon0

A. (?H/R) (1/T2 1/T1)

B. (1/R) (1/T1 1/T2)

C. (R/?H) (1/T1 1/T2)

D. (?H/R) (1/T1 1/T2)
212. Variation of equilibrium pressure with temperature for any two phases of a given substances is given by the ____________ equation?
comments icon0

A. None of these

B. Gibbs-Duhem

C. Clapeyron

D. Maxwells

213. In the reaction, C + O2 ? CO2; ?H = 94 kcal. What is the heat content (enthalpy) of O2 ?
comments icon0

A. -94 kcal

B. > -94 kcal

C. Zero

D. < 94 kcal

214. High pressure steam is expanded adiabatically and reversibly through a well insulated turbine, which produces some shaft work. If the enthalpy change and entropy change across the turbine are represented by ?H and ?S respectively for this process ?
comments icon0

A. ? H = 0 and ?S = 0

B. ? H ? 0 and ?S = 0

C. ? H = 0 and ?S ? 0

D. ? H ? 0 and ?S ? 0

215. The chemical potential of a component (?i) of a phase is the amount by which its capacity for doing all work, barring work of expansion is increased per unit amount of substance added for an infinitesimal addition at constant temperature and pressure. It is given by_________________?
comments icon0

A. (?H/?ni)S, P, nj

B. (?G/?ni)T, P, nj = (?A/?ni) T, v, nj

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

D. (?E/?ni)S, v, nj

216. In case of an _______________ process, the temperature of the system increases?
comments icon0

A. Adiabatic expansion

B. Isothermal expansion

C. Isothermal compression

D. Adiabatic compression
217. Joule-Thomson co-efficient which is defined as, ? = (?T/?P)H = 1/Cp (?H/?T)P, changes sign at a temperature known as inversion temperature. The value of Joule-Thomson co-efficient at inversion temperature is ___________________?
comments icon0

A. #NAME?

B. 0

C. ?

D. #NAME?

218. Compressibility factor for almost all the gases are approximately same at the same__________________?
comments icon0
A. Reduced pressure and reduced temperature

B. Critical pressure and critical temperature

C. Pressure and temperature

D. None of these

219. In case of the decomposition of hydroiodic acid (2HI ? H2 + I2), addition of H2 (at equilibrium condition) will__________________?
comments icon0
A. Diminish the degree of dissociation of HI

B. Increase the partial pressure of I2

C. None of these

D. Decrease the partial pressure of HI

220. PVy = constant, holds good for an isentropic process, which is_________________?
comments icon0

A. Adiabatic and irreversible

B. Reversible and isothermal

C. Reversible and adiabatic

D. Isothermal and irreversible

221. Gibbs-Helmholtz equation is__________________?
comments icon0
A. ?F = ?H + T [?(?F)/?T]P

B. d(E TS) T, V < 0

C. dP/dT = ?Hvap/T.?Vvap

D. ?F = ?H T?T

222. Specific _____________ does not change during phase change at constant temperature and pressure?
comments icon0

A. Internal energy

B. Enthalpy

C. Entropy

D. Gibbs energy
223. Which of the following will increase the volume of a real gas by four times ?
comments icon0
A. Reducing pressure to one fourth at constant temperature

B. Reducing the temperature to half and doubling the pressure

C. Doubling the absolute temperature as well as pressure of the gas

D. Reducing temperature to one fourth at constant pressure

224. In a homogeneous solution, the activity co-efficient of a component depends upon the_________________?
comments icon0

A. Pressure

B. Composition

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

D. Temperature

225. If the internal energy of an ideal gas decreases by the same amount as the work done by the system, then the____________________?
comments icon0

A. Process must be isobaric

B. Temperature must decrease

C. Process must be adiabatic

D. Both B. and C.
226. Solubility of a substance which dissolves with an increase in volume and liberation of heat will be favoured by the_______________?
comments icon0

A. High pressure and low temperature

B. Low pressure and low temperature

C. Low pressure and high temperature

D. High pressure and high temperature

227. Second law of thermodynamics is concerned with the_________________?
comments icon0

A. Non-cyclic processes only

B. Amount of energy transferred

C. Direction of energy transfer

D. Irreversible processes only

228. The total change in the enthalpy of a system is independent of the _______________________?
comments icon0

A. Pressure and temperature

B. None of these

C. State of combination and aggregation in the beginning and at the end of the reaction

D. Number of intermediate chemical reactions involved
229. Throttling process is a/an _____________ process?
comments icon0

A. Reversible and isothermal

B. Irreversible and constant enthalpy

C. Reversible and constant enthalpy

D. Reversible and constant entropy

230. Ideal refrigeration cycle is____________________?
comments icon0

A. Dependent on the refrigerants properties

B. The least efficient of all refrigeration processes

C. Same as Carnot cycle

D. Same as reverse Carnot cycle
231. Heat of reaction at constant volume is identified with _____________ change?
comments icon0

A. Either A. or B

B. Enthalpy

C. Internal energy

D. Neither A. nor B

232. The specific heat of saturated water vapour at 100C is__________________?
comments icon0

A. #NAME?

B. -ve

C. an data-mce-type="bookmark" style="width: 0px;overflow: hidden;line-height: 0" class="mce_SELRES_start">?</span>A. ?

D. 0

233. In the equation PVn = constant, if the value of n = y = Cp/Cv, then it represents a reversible ______________ process?
comments icon0

A. Isothermal

B. Isentropic

C. Adiabatic

D. Polytropic

234. Free energy___________________?
comments icon0

A. Decreases in all spontaneous (or irreversible) processes

B. All A, B. and C

C. Remains unchanged in reversible processes carried at constant temperature and pressure

D. Change during a spontaneous process has a negative value

235. _______________ increases with increase in pressure?
comments icon0

A. The melting point of wax

B. The boiling point of a liquid

C. Both A. and B

D. Neither A. nor B

236. Answer: Option B 392. Keeping the pressure constant, to double the volume of a given mass of an ideal gas at 27C, the temperature should be raised to _____________ C?
comments icon0

A. 300

B. 270

C. 327

D. 540

237. If we increase the pressure on a substance (which is at its triple point), then the triple point __________________?
comments icon0

A. May increase or decrease; depends on the substance

B. Remains unchanged

C. Decreases

D. Increases

238. Internal energy of an element at 1 atm and 25 C is ____________ kcal/kg.mole?
comments icon0
A. 0

B. 273

C. 25

D. None of these

239. Gibbs free energy of a pure fluid approaches _____________ as the pressure tends to zero at constant temperature?
comments icon0
A. Minus infinity

B. None of these

C. Infinity

D. Zero

240. In the decomposition of PCl5 represented by, PCl5 ? PCl3 + Cl2, decrease in the pressure of the system will _____________ the degree of dissociation of PCl5?
comments icon0
A. Increase

B. Decrease

C. Not alter

D. None of these

241. Charles law for gases states that__________________?
comments icon0

A. V ? 1/P

B. V/T = Constant

C. V ? 1/T

D. PV/T = Constant

242. The theoretical minimum work required to separate one mole of a liquid mixture at 1 atm, containing 50 mole % each of n- heptane and n- octane into pure compounds each at 1 atm is__________________?
comments icon0
A. -RT ln 0.5

B. 2 RT

C. 0.5 RT

D. -2 RT ln 0.5

243. Joule-Thomson co-efficient depends on the_____________________?
comments icon0

A. Pressure

B. Temperature

C. Both A. & B

D. Neither A. nor B

244. Free energy, fugacity and activity co-efficient are all affected by change in the temperature. The fugacity co-efficient of a gas at constant pressure ______________ with the increase of reduced temperature?
comments icon0

A. Decreases logarithmically

B. Decreases

C. Increases

D. Remains constant

245. For the reversible exothermic reaction, N2 + 3H2 ? 2NH3, increase of pressure would________________?
comments icon0

A. Shift the equilibrium towards right

B. Give higher yield of NH3

C. Both B. and C

D. Neither A. nor B

246. Isotherm on an enthalpy-concentration diagram, for an ideal solution will be a __________________?
comments icon0

A. Sine curve

B. Straight line

C. Parabola

D. Hyperbola

247. Measurement of thermodynamic property of temperature is facilitated by ____________ law of thermodynamics?
comments icon0
A. Zeroth

B. None of these

C. 3rd

D. 1st

248. _____________ calorimeter is normally used for measuring the dryness fraction of steam, when it is very low?
comments icon0

A. Separating

B. Throttling

C. A combination of separating & throttling

D. Bucket

249. For multi-component multiple phases to be in equilibrium at the same pressure and temperature, the _______________ of each component must be same in all phases?
comments icon0

A. Chemical potential

B. Fugacity

C. Both A. and B

D. Neither A. nor B

250. In the equation, PVn = constant, if the value of n is in between 1 and y (i.e. Cp/Cv), then it represents a reversible ____________ process?
comments icon0

A. Isentropic

B. Isometric

C. Isobaric

D. Polytropic