chemical engineering thermodynamics for chemical chemical engineering Mcqs
351. Maximum work that could be secured by expanding the gas over a given pressure range is the _____________ work?
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A. Adiabatic

B. Isentropic

C. Isothermal

D. None of these

352. The heat capacities for the ideal gas state depend upon the_________________?
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A. Pressure

B. Temperature

C. Both A. & B.

D. Neither A. nor B.

353. Mollier chart is a _____________ plot?
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A. Enthalpy vs. entropy

B. Pressure vs. enthalpy

C. Pressure vs. volume

D. Temperature vs. entropy

354. The expression, nRT ln(P1/P2), is for the _____________of an ideal gas?
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A. Work done under adiabatic condition

B. Co-efficient of thermal expansion

C. Compressibility

D. Work done under isothermal condition
355. 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_________________?
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A. 6 P1 V1

B. 3 P1V1

C. 12 P1V1

D. P1 V1

356. A/an ____________ system is exemplified by a vessel containing a volatile liquid in contact with its vapor?
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A. Closed

B. Open

C. Isolated

D. None of these

357. For any system, what is the minimum number of degrees of freedom ?
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A. 2

B. 1

C. 3

D. 0
358. The partial pressure of each constituent present in an alloy is _____________ the total vapor pressure exerted by the alloy?
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A. Equal to

B. Either B. or C; depends on the type of alloy

C. More than

D. Less than
359. Fundamental principle of refrigeration is based on the ______________ law of thermodynamics?
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A. Third

B. Zeroth

C. Second

D. First

360. Which of the following liquid metals has the highest thermal conductivity ?
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A. Molten sodium

B. Molten lead

C. Molten potassium

D. Mercury

361. Pick out the correct equation relating F and A___________________?
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A. F = A + PV

B. F = E + A

C. F = A TS

D. F = A + TS

362. Critical compressibility factor for all substances___________________?
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A. Vary as square of the absolute temperature

B. None of these

C. Vary as square of the absolute pressure

D. Are more or less constant (vary from 0.2 to 0.3)
363. The change in Gibbs free energy for vaporisation of a pure substance is___________________?
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A. May be positive or negative

B. Zero

C. Positive

D. Negative

364. Entropy change for an irreversible isolated system is__________________?
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A. < 0

B. 0

C. > 0

D. ?

365. With increase in compression ratio, the efficiency of the otto engine________________?
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A. Increases linearly

B. Decreases

C. Increases

D. Remain constant

366. A refrigeration cycle is a reversed heat engine. Which of the following has the maximum value of the co-efficient of performance (COP) for a given refrigeration effect ?
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A. Carnot refrigeration cycle

B. Vapor compression cycle using expansion valve

C. Air refrigeration cycle

D. Vapor compression cycle using expansion engine

367. Absorption/evolution of heat during conversion of a substance from one allotropic form to another is termed as the heat of _____________________?
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A. Sublimation

B. Transition

C. Fusion

D. Vaporisation

368. The freezing point of a liquid decreases when the pressure is increased, if the liquid ____________ while freezing?
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A. Does not change in volume

B. Either (A), B. or (C)

C. Expands

D. Contracts
369. On opening the door of an operating refrigerator kept in a closed room, the temperature of the room will____________________?
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A. Increase in summer and will decrease in winter

B. Increase

C. Decrease

D. Remain same

370. The necessary condition for phase equilibrium in a multiphase system of N components is that the____________________?
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A. Chemical potentials of a given component should be equal in all phases

B. Chemical potentials of all components should be same in a particular phase

C. Sum of the chemical potentials of any given component in all the phases should be the same

D. None of these

371. The chemical potential of any constituent of an ideal solution depends on the ______________ of the solution?
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A. Composition

B. Temperature

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

D. Pressure

372. At 60 C, vapour pressure of methanol and water are 84.562 kPa and 19.953 kPa respectively. An aqueous solution of methanol at 60 C exerts a pressure of 39.223 kPa; the liquid phase and vapour phase mole fractions of methanol are 0.1686 and 0.5714 respectively. Activity co-efficient of methanol is__________________?
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A. 4.238

B. 1.572

C. 1.9398

D. 3.389

373. Adiabatic compression of a saturated water vapour makes it ____________________ ?
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A. Supersaturated

B. Superheated

C. Both A. and B

D. Neither A. nor B

374. Refrigeration cycle_________________?
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A. Violates second law of thermodynamics

B. Involves transfer of heat from low temperature to high temperature

C. Both A. and B

D. Neither A. nor B

375. For water at 300C, 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 cm3 and that in vapour phase in 391.1 cm3.Fugacity of water (in kPa) at 9000 kPa will be__________________?
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A. 6753.5

B. 7058.3

C. 9000

D. 6738.9

376. The principle applied in liquefaction of gases is_____________________?
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A. Adiabatic expansion

B. Joule-Thomson effect

C. Both A. and B

D. Neither A. nor B

377. Which of the following is a widely used refrigerant in vapour compression refrigeration system (using large centrifugal compressor) ?
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A. Ammonia

B. Freon

C. Methyl chloride

D. Liquid sulphur dioxide

378. 1st law of thermodynamics is nothing but the law of conservation of___________________?
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A. None of these

B. Energy

C. Momentum

D. Mass

379. The expression, ?G = nRT. ln(P2/P1), gives the free energy change______________?
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A. During heating of an ideal gas

B. During cooling of an ideal gas

C. Under reversible isothermal volume change

D. With pressure changes at constant temperature
380. The expression for the work done for a reversible polytropic process can be used to obtain the expression for work done for all processes, except reversible _____________ process?
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A. Adiabatic

B. Isothermal

C. None of these

D. Isobaric

381. Number of components (C), phase (P) and degrees of freedom (F) are related by Gibbs phase rule as________________?
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A. C = P F + 2

B. P + F C = 2

C. P = F C 2

D. F = C P 2

382. A system is said to be at equilibrium, if the entropy of the system has reached ____________ value?
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A. Zero

B. Maximum

C. Minimum

D. None of these

383. What happens in a reversible adiabatic expansion process ?
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A. Cooling takes place

B. Heating takes place

C. Temperature is constant

D. Pressure is constant

384. Cv for an ideal gas__________________?
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A. Does not depend upon temperature

B. Is independent of pressure only

C. Is independent of volume only

D. Is independent of both pressure and volume
385. Isobaric process means a constant process ?
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A. Temperature

B. Entropy

C. Volume

D. Pressure
386. Cp of a gas at its critical temperature and pressure_______________?
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A. Becomes infinity

B. Equals 0.24 kcal/kmol K

C. Becomes zero

D. Equals 1 kcal/kmol K

387. Rotary lime kiln is an example of a/an _____________ system?
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A. Isolated

B. Closed

C. Open

D. Non-thermodynamic

388. Pick out the undesirable property for a good refrigerant ?
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A. Low freezing point

B. High viscosity

C. High thermal conductivity

D. Large latent heat of vaporisation

389. For an ideal gas, the activity co-efficient is_________________?
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A. None of these

B. Directly proportional to pressure

C. Unity at all pressures

D. Inversely proportional to pressure

390. If atmospheric temperature and dew point are nearly equal, then the relative humidity is_______________?
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A. Zero

B. Almost 100%

C. unpredictable

D. 50%

391. The Carnot co-efficient of performance (COP) of a domestic air conditioner compared to a household refrigerator is__________________?
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A. Less

B. Dependent on climatic conditions

C. More

D. Same

392. If the vapour pressure at two temperatures of a solid phase in equilibrium with its liquid phase are known, then the latent heat of fusion can be calculated by the _________________?
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A. Nernst Heat Theorem

B. Clausius-Clapeyron Equation

C. Van Laar equation

D. Maxwells equation

393. For a stable phase at constant pressure and temperature, the fugacity of each component in a binary system _____________ as its mole fraction increases?
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A. Decreases linearly

B. Remain same

C. Decreases

D. Increases
394. Fugacity co-efficient of a substance is the ratio of its fugacity to__________________?
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A. Pressure

B. Activity co-efficient

C. Activity

D. Mole fraction

395. The enthalpy change when ammonia gas is dissolved in water is called the heat of___________________?
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A. Solution

B. Dilution

C. Formation

D. Combustion

396. High _____________ is an undesirable property for a good refrigerant?
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A. Viscosity

B. Specific heat

C. Latent heat of vaporisation

D. Specific vapor volume

397. Which of the following is not an intensive property ?
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A. Internal energy

B. None of these

C. Viscosity

D. Molar heat capacity

398. For an irreversible process involving only pressure-volume work____________________?
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A. (dF)T, p > 0

B. (dF)T, p = 0

C. (dA)T, v >0

D. (dF)T, p
399. In an irreversible process________________?
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A. dE dW Tds = 0

B. Tds dE + dW < 0

C. Tds dT + dW < 0

D. Tds = dE dW = 0

400. Internal energy change of a system over one complete cycle in a cyclic process is__________________?
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A. #NAME?

B. Zero

C. #NAME?

D. Dependent on the path