chemical engineering MCQs – Page 94

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 Review each marked answer and report any item that may be outdated or unclear.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
1861. In case of constant underflow extraction operation, the _______________________ at all solute concentration?
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A. Solids are drained to the same extent

B. Ratio of the insoluble to solution is constant

C. Both A. & B.

D. Neither A. nor B.

1862. Binary distillation involves the mass transfer by ______________________ at the gas-liquid interface?
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A. Unidirectional diffusion from gas to liquid phase

B. A counter diffusion at an almost equal molar rate

C. Unidirectional diffusion from liquid to gas phase

D. Either A. or B.

1863. The reflux to a distillation column is 100 moles/hr, when the overhead product rate is 50 moles/hr. The reflux ratio is____________________?
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A. 2

B. 0.5

C. 150

D. 50

1864. ___________________ extractor uses centrifugal force for separating the two phases?
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A. Treybal

B. Podbielniak

C. None of these

D. Scheibel

1865. The reason for preferring packed towers over plate towers in distillation practice is that the packed tower operation gives___________________?
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A. High pressure drop and low hold up

B. High pressure drop and high hold up

C. Low pressure drop and low hold up

D. Low pressure drop and high hold up

1866. The ratio of Murphree plate efficiency to point efficiency is always > 1 in a _______________ flow model?
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A. Plug

B. Perfectly mixed

C. Both A. & B.

D. Neither A. nor B.

1867. Pick out the wrong statement?
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A. Eosin requirement in tallow soap is about 40-50% which fastens the lather formation, softens

B. tea, blood etc</strong>

C. hard soaps and increases its cleansing action

D. Soap powder is prepared by mixing soap with hydrated sodium carbonate

E. Detergents differ from soaps in their action in hard water

F. Tarnish inhibitor (e.g., Benzotriazole) is added in soap to facilitate the removal of stains due
1868. __________________ is concerned with the adsorption equilibria?
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A. Ficks law

B. Freundlich equation

C. None of these

D. Gibbs equation

1869. In case of an ideal solution, the total vapor pressure varies ______________ with the composition expressed as mole fraction?
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A. Exponentially

B. None of these

C. Linearly

D. Inversely

1870. Even though bubble cap towers are very effective for humidification operation, they are not used commonly in industries, because of the_________________?
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A. None of these

B. High pressure drop of the gas

C. High evaporation losses of water

D. Difficulty in its fabrication

1871. For a single component absorber, the operating line is straight only when plotted in term of ______________ units?
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A. Mole fraction

B. Mole ratio

C. None of these

D. Partial pressure

1872. Molecular distillation is_____________________?
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A. High temperature distillation

B. For heat-sensitive materials

C. Very low pressure distillation

D. Both B. and C.
1873. NSc/NPr is called the______________________?
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A. Lewis number

B. Psychrometric ratio

C. Sherwood number

D. Stanton number

1874. The most economical range of absorption factor is____________________?
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A. 1.25 to 2

B. 0 to 0.5

C. 0 to 3

D. 5 to 15

1875. The relation, Sc = Pr = 1, is valid, when the mechanism of ______________ transfer is same?
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A. Heat, momentum and mass

B. Mass and momentum

C. Heat and mass

D. Heat and momentum

1876. _______________ extractor is used for the concentration of radioactive nuclear waste?
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A. Pulsed column

B. Sieve plate

C. Mixer-settler

D. Bollman

1877. Gaseous diffusivity at atmospheric pressure is of the order of _____________________ cm2/second?
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A. 1 to 5

B. > 10

C. 1

D. 5 to 10

1878. Schmidt number and Lewis number for pure air at atmospheric conditions are respectively__________________?
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A. < 1 and ? 1

B. 0 and ? 1

C. 1 and 0

D. > 1 and ? 1

1879. With decrease in the throughput (compared with the design capacity) for a bubble cap distillation column, its efficiency____________________?
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A. Increases

B. Remain same

C. May increase or decrease; depends on individual design

D. Decreases

1880. Which of the following is a suitable absorbent for removal of H2S from natural gas ?
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A. Monoethanolamine (MEA)

B. Hot water

C. Dilute

D. Vetrocoke solution