chemical engineering MCQs – Page 99

Practise multiple-choice questions from chemical engineering for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

chemical engineering Mcqs
1961. With the lowering of equilibrium pressure, at a given temperature, the amount of adsorbate on the adsorbent______________________?
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A. Increases

B. Remain same

C. Decreases

D. Either A. or B., depends on the system

1962. At the boiling point of the liquid at the prevailing pressure, the saturated absolute humidity becomes______________________?
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A. ?

B. None of these

C. 0

D. 1

1963. Bound moisture is that liquid which exerts an equilibrium vapor pressure ________________ that of the pure liquid at the given temperature ?
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A. More than

B. Less than

C. Equal to

D. Either A. or B.; depends on the solid

1964. Drying of a wet solid under constant drying conditions means the exposure of the wet solid to the air of constant____________________?
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A. Temperature

B. Velocity

C. All A., B. & C.

D. Humidity

1965. Which of the following operations does not involve leaching ?
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A. Removing nicotine from its water solution by kerosene

B. Dissolving pharmaceutical products from bark or roots

C. Dissolving sugar from the cells of the beet

D. Dissolving gold from ores

1966. Freundlich equation applies to the adsorption of solute from_____________________?
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A. Dilute solutions, over a small concentration range

B. Gaseous solutions at high pressure

C. Concentrated solutions

D. None of these

1967. During constant rate period, the rate of drying decreases with the______________________?
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A. Decrease in air temperature

B. Increase in air humidity

C. Both A. and B.

D. Neither A. nor B.

1968. Use of natural draft cooling tower is practised, when the air has low ?
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A. Humidity

B. Temperature

C. Both A. & B.

D. Neither A. nor B.

1969. Pick out the wrong statement pertaining to the analogy between equations of heat and mass_________________?
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A. nsfer operations.

B. Sherwood number in mass transfer is analogous to Nusselt number in heat transfer

C. Prandtl number in heat transfer is analogous to Schmidt number in mass transfer

D. Reynolds number in mass transfer is analogous to Grashoff number in heat transfer

E. Reynolds number remains the same in both heat and mass transfer

1970. The slope of the operating line for a single component co-current absorber when plotted in terms of mole ratio units is__________________?
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A. #NAME?

B. -ve

C. ?

D. 0

1971. Plate towers are preferred to packed towers, when large temperature changes are involved, because of the reason that the____________________?
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A. None of these

B. Packing may be crushed due to thermal expansion/contraction of the components of the

C. Pressure drop in the equipment will be very high

D. ipments</strong>

E. Viscosity variation of the fluids may cause channelling/flooding

1972. Rayleighs equation applies to _________________ distillation?
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A. Flash

B. Continuous

C. Differential

D. Steam

1973. With increase in temperature, the rate of leaching increases, because the___________________?
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A. Diffusivity of solute increases

B. Thermal conductivity of solute increases

C. None of these

D. Viscosity of solvent decreases

1974. Very tall packed towers are divided into series of beds to___________________?
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A. Avoid channelling

B. Reduce liquid hold-up

C. Avoid flooding

D. Reduce the overall pressure drop

1975. The slope of 9-line is determined by the______________________?
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A. Reflux ratio

B. Thermal condition of the feed

C. Plate efficiency to be achieved

D. Relative volatility

1976. The McCabe ?L law states that the____________________?
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A. Linear crystal growth rate depends on the crystal size

B. Linear crystal growth rate does not depend on the crystal size

C. Linear crystal growth rate depends on the degree of super-saturation

D. Molar heats of vaporisation of components are nearly equal

1977. Steam distillation is used for separation of high boiling ____________________?
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A. Substances from non-volatile impurities

B. Volatile impurity from still higher boiling substances

C. Both A. and B.

D. Neither A. nor B.

1978. Penetration model (theory) for mass transfer was enunciated by _____________________?
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A. Higbie

B. Toor and Marcello

C. Kissinevskii

D. Danckwerts

1979. For experimental determination of mass transfer co-efficient by wetted wall tower, the mass transfer area is___________________?
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A. Calculated

B. Unknown

C. Known

D. Not required

1980. The minimum liquid rate to be used in an absorber corresponds to an operating line_______________________?
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A. Of slope = 1

B. Of slope = 0.1

C. None of these

D. Tangential to the equilibrium curve