chemical engineering Mcqs
8251. 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. Same

C. More

D. Dependent on climatic conditions

8252. 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 ?
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A. ? H = 0 and ?S = 0

B. ? H ? 0 and ?S ? 0

C. ? H = 0 and ?S ? 0

D. ? H ? 0 and ?S = 0
8253. When liquid and vapour phases of one component system are in equilibrium (at a given temperature and pressure), the molar free energy is__________________?
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A. More in vapour phase

B. More in liquid phase

C. Same in both the phases

D. Replaced by chemical potential which is more in vapour phase

8254. During a reversible isothermal expansion of an ideal gas, the entropy change is_________________?
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A. #NAME?

B. 0

C. ?

D. +ve
8255. 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 ___________________?
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A. #NAME?

B. #NAME?

C. 0

D. ?

8256. In case of the decomposition of hydroiodic acid (2HI ? H2 + I2), addition of H2 (at equilibrium condition) will__________________?
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A. Increase the partial pressure of I2

B. Diminish the degree of dissociation of HI

C. Decrease the partial pressure of HI

D. None of these

8257. Which of the following is Clausius-Clapeyron Equation for vaporisation of an ideal gas under the condition that the molar volume of liquid is negligible compared to that of the vapor ?
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A. dp/dt = Hvap/RT2

B. d ln p/dt = Hvap/RT2

C. dp/dt = RT2/Hvap

D. d ln p/dt = RT2/Hvap

8258. The ratio of equilibrium constants (Kp2/Kp1) at two different temperatures is given by____________________?
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A. (?H/R) (1/T1 1/T2)

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

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

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

8259. Gibbs-Helmholtz equation is__________________?
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A. ?F = ?H T?T

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

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

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

8260. Dry ice is________________?
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A. Moisture free ice

B. None of these

C. Solid helium

D. Solid carbon dioxide
8261. With increase in reduced temperature, the fugacity co-efficient of a gas at constant reduced pressure___________________?
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A. Decreases

B. Remain same

C. Decreases linearly

D. Increases
8262. As pressure approaches zero, the ratio of fugacity to pressure (f/P) for a gas approaches____________________?
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A. Zero

B. An indeterminate value

C. Unity

D. Infinity

8263. Which of the following is Virial equation of state ?
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A. None of these

B. PV = nRT

C. (p + a/V2)(V b) = nRT

D. PV = A + B/V + C/V2 + D/V3 +
8264. The absolute entropy for all crystalline substances at absolute zero temperature is ____________________?
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A. Zero

B. More than zero

C. Indeterminate

D. Negative

8265. Fugacity is most helpful in____________________?
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A. The study of chemical equilibria involving gases at atmospheric pressure

B. Representing actual behaviour of real gases

C. Representing actual behaviour of ideal gases

D. None of these

8266. 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

8267. Refrigerants commonly used for domestic refrigerators are_________________?
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A. Freon-12

B. NH3 or CO2

C. Ethyl chloride or methyl chloride

D. Propane

8268. The gas law (PV = RT) is true for an ______________ change?
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A. Isothermal

B. Adiabatic

C. Both A. & B

D. Neither A. nor B

8269. The extensive properties are____________________?
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A. Volume, mass and number of moles

B. Free energy, entropy and enthalpy

C. Both A. and B

D. None of these

8270. Internal energy of an ideal gas___________________?
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A. Is independent of temperature

B. None of these

C. Increases with increase in pressure

D. Decreases with increase in temperature

8271. The four properties of a system viz. P, V, T, S are related by ______________ equation?
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A. Maxwells

B. Gibbs-Duhem

C. None of these

D. Gibbs-Helmholtz

8272. Recycling in a chemical process facilitates___________________?
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A. Heat conservation

B. All A., B. & C.

C. Increased yield

D. Enrichment of product

8273. Refrigeration capacity of a household refrigerator may be round about _____________ tons?
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A. 1.5

B. 6.5

C. 4.5

D. 0.15
8274. The melting point of paraffin wax (which contracts on solidification) _______________ with pressure rise?
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A. Increases

B. Decreases linearly

C. Remains unchanged

D. Decreases

8275. Entropy change of mixing two liquid substances depends upon the_________________?
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A. Molar concentration

B. Quantity (i.e. number of moles)

C. Both A. and B

D. Neither A. nor B

8276. 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. Dimensionless, when ?x = 0

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

C. (atm)?x2, when ?x > 0

D. (atm)?x, when ?x is negative

8277. Heat of transition is the heat evolved or absorbed, when a substance is converted from_________________?
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A. Solid to liquid

B. One allotropic form to another allotropic form

C. Vapor to solid

D. Vapor to liquid

8278. What is the value of ln y (where y = activity co-efficient) for ideal gases ?
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A. Unity

B. Zero

C. Negative

D. Infinity

8279. PV? = Constant (where, ? = Cp/Cv) is valid for a/an ______________ process?
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A. Isothermal

B. Isentropic

C. Adiabatic

D. Isobaric

8280. For a constant volume process _____________ by the system is used only to increase the internal energy?
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A. Heat absorbed

B. Work done

C. Both A. & B

D. Neither A. nor B

8281. Which of the following liquid metals has the highest thermal conductivity ?
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A. Molten sodium

B. Mercury

C. Molten potassium

D. Molten lead

8282. Raoults law is not applicable to the___________________?
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A. Solutes which dissociate or associate in the particular solution

B. Concentrated solutions

C. Both B. & C.

D. Solutions containing non-volatile solute

8283. The main feature of Carnot refrigeration cycle is that, it________________________?
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A. None of these

B. Accomplishes the reverse effect of the heat engine

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

D. Transfers heat from high temperature to low temperature

8284. The number of degrees of freedom for an azeotropic mixture in a two component vapourliquid equilibria is/are__________________?
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A. Zero

B. Three

C. Two

D. One
8285. 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.

8286. Specific _____________ does not change during phase change at constant temperature and pressure?
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A. Entropy

B. Enthalpy

C. Gibbs energy

D. Internal energy

8287. The temperature at which a real gas obeys Boyles law is termed as the__________________?
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A. Eutectic point

B. Inversion temperature

C. Triple point

D. Boyles temperature
8288. 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. Decreases

C. Increases

D. Decreases exponentially

8289. Degree of freedom of a system consisting of a gaseous mixture of H2 and NH3 will be_________________?
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A. 2

B. 1

C. 3

D. 0

8290. Internal energy is equal to the heat absorbed in case of a/an ______________ process?
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A. Constant volume

B. Polytropic

C. Adiabatic

D. Constant pressure

8291. The number of degrees of freedom at the triple point of water is__________________?
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A. 2

B. 3

C. 0

D. 1

8292. 1m3 is approximately equal to_________________?
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A. 28 litres

B. 4.5 litres

C. 35 ft3

D. 4.5 ft3

8293. 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
8294. Two substances are in equilibrium in a reversible chemical reaction. If the concentration of each substance is doubled, then the value of the equilibrium constant will be___________________?
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A. One fourth of its original value

B. Doubled

C. Halved

D. Same
8295. At a constant volume, for a fixed number of moles of a gas, the pressure of the gas increases with rise of temperature due to___________________?
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A. Increased collision rate among molecules

B. Decrease in mean free path

C. Increase in molecular attraction

D. Increase in average molecular speed

8296. The compressibility factor of a gas is given by (where, V1 = actual volume of the gas V2 = gas volume predicted by ideal gas law)____________________?
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A. V1/V2

B. V2/V1

C. V1 V2

D. V1.V2

8297. Which of the following behaves most closely like an ideal gas ?
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A. H2

B. O2

C. He

D. N2

8298. Translational kinetic energy of molecules of an ideal gas is proportional to (where, T = absolute temperature of the gas)__________________?
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A. T

B. ?T

C. 1/?T

D. T2

8299. The Joule-Thomson co-efficient is defined as (?T/?P)H. Its value at the inversion point is__________________?
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A. #NAME?

B. 1

C. ?

D. 0
8300. PVy = constant, holds good for an isentropic process, which is_________________?
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A. Reversible and isothermal

B. Isothermal and irreversible

C. Adiabatic and irreversible

D. Reversible and adiabatic