chemical engineering thermodynamics for chemical chemical engineering Mcqs
251. Gibbs phase rule finds application, when heat transfer occurs by___________________?
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A. Conduction

B. Radiation

C. Convection

D. Condensation
252. With increase in pressure (above atmospheric pressure), the Cp of a gas_____________________?
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A. Decreases

B. Increases

C. Remains unchanged

D. First decreases and then increases

253. For organic compounds, group contribution method can be used for the estimation of _____________________?
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A. Critical properties

B. Specific gravity

C. Specific volume

D. Thermal conductivity

254. For a real gas, the chemical potential is given by_____________________?
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A. None of these

B. RT d ln P

C. RT d ln f

D. R d ln f

255. Fugacity is a measure of the____________________?
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A. None of these

B. Behaviour of ideal gases

C. Relative volatility of a mixture of two miscible liquids

D. Escaping tendencies of the same substance in different phases of a system
256. Molar heat capacity of water in equilibrium with ice at constant pressure is __________ Kcal/kg mole. K___________________?
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A. 50

B. ?

C. 100

D. 0

257. Which is a state function ?
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A. Pressure

B. Work

C. Temperature

D. Specific volume

258. The ammonia synthesis reaction represented by N2 + 3H2 ? 2NH3; ?H = 22.4 kcal, is__________________?
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A. Isothermal

B. Endothermic

C. Exothermic

D. Adiabatic

259. Pick out the Clausius-Clapeyron equation from the following?
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A. dP/dT = ?H/T?V

B. None of these

C. ln P = (?H/RT) + constant

D. ?F = ?H + T [?(?F)/?T]P

260. Gases are cooled in Joule-Thomson expansion, when it is _____________ inversion temperature?
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A. Below

B. Above

C. At

D. Either B. or C.

261. A cylinder contains 640 gm of liquid oxygen. The volume occupied (in litres) by the oxygen, when it is released and brought to standard conditions (0C, 760 mm Hg) will be _____________ litres?
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A. Data insufficient; cant be computed

B. 448

C. 22.4

D. 224

262. In case of vapour compression refrigeration system, elevating the evaporator temperature (keeping the condenser temperature constant) results in_____________?
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A. No change in the value of COP

B. Enhanced COP

C. Decreased COP

D. Increased or decreased COP; depending upon the type of refrigerant

263. Pick out the wrong statement ?
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A. The gases which are capable of forming ions in aqueous solution are much more soluble in

B. At constant pressure, solubility of a gas in a liquid diminishes with rise in temperature

C. er than in other solvents

D. At constant pressure, solubility of a gas in a liquid increases with rise in temperature

E. Normally, the gases which are easily liquefied are more soluble in common solvents

264. What is the value of Joule-Thomson co-efficient for an ideal gas ?
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A. ?

B. #NAME?

C. 0

D. #NAME?

265. Melting of ice is an example of an _____________ process?
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A. Isometric

B. None of these

C. Isothermal

D. Adiabatic

266. As pressure approaches zero, the ratio of fugacity to pressure (f/P) for a gas approaches____________________?
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A. An indeterminate value

B. Infinity

C. Zero

D. Unity
267. Consider the reaction, C + O2 ? CO2; ?H = 94 kcal. What will be the value of ?H for the reaction CO2 ? C + O2 ?
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A. < -94 kcal

B. -94 kcal

C. +94 kcal

D. > 94 kcal

268. The work done in an adiabatic change in a particular gas depends upon changes in the ______________ only?
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A. Temperature

B. Pressure

C. Volume

D. Specific heat

269. At absolute zero temperature, the _____________ of the gas is zero?
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A. None of these

B. Volume

C. Mass

D. Pressure

270. The quantitative effect of temperature on chemical equilibrium is given by the____________________?
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A. Le-Chateliers principle

B. None of these

C. Arrhenius equation

D. Vant-Hoff equation
271. For a given substance at a specified temperature, activity is ______________ to fugacity?
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A. Equal

B. Inversely proportional

C. None of these

D. Directly proportional
272. Equilibrium constant decreases as the temperature___________________?
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A. Decreases, for an exothermic reaction

B. Increases, for an endothermic reaction

C. Increases, for an exothermic reaction

D. None of these

273. The main feature of Carnot refrigeration cycle is that, it________________________?
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A. Transfers heat from high temperature to low temperature

B. Accomplishes the reverse effect of the heat engine

C. None of these

D. Does not need the addition of external work for its functioning

274. No work is done by the system, when a reaction occurs at constant__________________?
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A. Volume

B. Temperature

C. None of these

D. Pressure

275. For a spontaneous process, free energy__________________?
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A. Is zero

B. Increases

C. Decreases whereas the entropy increases

D. And entropy both decrease

276. The unit of fugacity is the same as that of the_________________?
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A. Pressure

B. Volume

C. Molar concentration

D. Temperature

277. At the critical point of a substance____________?
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A. Liquid and vapour have the same density

B. There is no distinction between liquid and vapour phases

C. All A, B. and C

D. The surface tension vanishes

278. Heat is added at constant pressure in an ideal _____________ cycle?
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A. Stirling

B. Brayton

C. Rankine

D. Both B. and C
279. Which law of the thermodynamics provides basis for measuring the thermodynamic property ?
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A. Second law

B. Third law

C. First law

D. Zeroth law
280. Which of the following represents the Virial equation of state ?
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A. T = [RT/(V- b)] [a/?T. V(V + b)]

B. None of these

C. PV/RT = 1 + (B/V) + (C/V2) +

D. n1u2 + ?2?1 = 0

281. For an ideal gas, the internal energy depends upon its ____________ only?
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A. Temperature

B. Molecular size

C. Pressure

D. Volume

282. Which of the following is not affected by temperature changes ?
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A. None of these

B. Activity co-efficient

C. Fugacity

D. Free energy

283. Filling of gas from a high pressure cylinder into small bottles is an example of a/an ______________ process?
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A. Adiabatic

B. Steady

C. Unsteady

D. Equilibrium

284. If different processes are used to bring about the same chemical reaction, the enthalpy change is same for all of them. This is ______________ law?
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A. Hesss

B. Lavoisier and Laplace

C. Kirchoffs

D. None of these

285. The number of degrees of freedom for an azeotropic mixture in a two component vapourliquid equilibria is/are__________________?
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A. One

B. Zero

C. Three

D. Two

286. The temperature at the eutectic point of the system is the _____________ temperature that can be attained in the system?
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A. None of these

B. Highest

C. Lowest

D. Average

287. In case of steady flow compression polytropic process (PVn = constant), the work done on air is the lowest, when_______________?
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A. n = 1.66

B. n = 0

C. n = 1

D. n = y = 1.4

288. The equation, PV = nRT, is best obeyed by gases at____________________?
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A. None of these

B. Low pressure & high temperature

C. High pressure & low temperature

D. Low pressure & low temperature

289. The point at which all the three (solid, liquid and gas) phases co-exist, is known as the ____________ point?
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A. Freezing

B. Boiling

C. Boyle

D. Triple
290. On a P-V diagram of an ideal gas, suppose a reversible adiabatic line intersects a reversible isothermal line at point A. Then at a point A, the slope of the reversible adiabatic line (?P/?V)s and the slope of the reversible isothermal line (?P/?V)T are related as (where, y = Cp/Cv) ?
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A. (?P/?V)S = 1/y(?P/?V)T

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

C. (?P/?V)S = [(?P/?V)T]Y

D. (?P/?V)S = y(?P/?V)T
291. The effect of changing the evaporator temperature on COP as compared to that of changing the condenser temperature (in vapour compression refrigeration system) is__________________?
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A. Data insufficient, cant be predicted

B. More pronounced

C. Less pronounced

D. Equal

292. Entropy of an ideal gas depends upon its__________________?
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A. Pressure

B. Temperature

C. Both A. & B

D. Neither A. nor B

293. When a system is in equilibrium for all possible processes, the differential or finite change of entropy is__________________?
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A. < 0

B. 0

C. None of these

D. > 0

294. ______________ Equation predicts the activity co-efficient from experimental data ?
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A. Lewis-Randall

B. Margules

C. Van Laar

D. Both B. & C.
295. The following heat engine produces power of 100,000 kW. The heat engine operates between 800 K and 300 K. It has a thermal efficiency equal to 50% of that of the Carnot engine for the same temperature. The rate at which heat is absorbed from the hot reservoir is____________________?
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A. 320,000 kW

B. 200,000 kW

C. 160,000 kW

D. 100,000 kW

296. In jet refrigerators, the refrigerating fluid is practically always_________________?
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A. Water

B. Freon

C. Ammonia

D. Brine

297. Thermal efficiency of a Carnot engine can approach 100%, only when the temperature of the__________________?
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A. Cold reservoir approaches zero

B. Hot reservoir approaches infinity

C. Either A. or B

D. Neither A. nor B

298. The free energy change for a chemical reaction is given by (where, K = equilibrium constant)________________?
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A. -RT ln K

B. T ln K

C. RT ln K

D. -R ln K

299. Entropy change of the reaction, H2O (liquid) ? H2O (gas), is termed as the enthalpy of___________________?
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A. Formation

B. Sublimation

C. Vaporisation

D. Solution

300. If the heat of solution of an ideal gas in a liquid is negative, then its solubility at a given partial pressure varies with the temperature as__________________?
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A. Solubility increases or decreases with temperature depending on the Gibbs free energy change

B. Solubility increases as temperature increases

C. Solubility is independent of temperature

D. Solubility increases as temperature decreases

E. solution