chemical engineering MCQs – Page 93

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 Review each marked answer and report any item that may be outdated or unclear.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
1841. Acetic acid will be most economically separated from a dilute solution of acetic acid in water by____________________?
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A. Evaporation

B. Continuous distillation

C. Absorption

D. Solvent extraction
1842. It takes 6 hours to dry a wet solid from 50% moisture content to the critical moisture content of 15%. How much longer it will take to dry the solid to 10% moisture content, under the same drying conditions? (The equilibrium moisture content of the solid is 5%) ?
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A. 51 min

B. 71 min

C. 15 min

D. 94 min

1843. In the constant rate period of the rate of drying curve for batch drying,_________________?
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A. Rate of drying decreases abruptly

B. None of these

C. Cracks develop on the surface of the solid

D. Surface evaporation of unbound moisture occurs
1844. Mass transfer co-efficient is directly proportional to DAB according to the __________ theory?
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A. Film

B. None of these

C. Penetration

D. Surface-renewal

1845. Dorr thickener is an equipment used for______________________?
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A. Classification

B. Sedimentation

C. Leaching

D. Clarification

1846. At __________________ reflux, theoretical number of plates in a distillation coloumn is calculated using Fenske-Underwood equation?
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A. Maximum permissible

B. Operating

C. Total

D. Minimum

1847. The value of Lewis number (Le = Sc/Pr) for air-water vapour system is around_________________?
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A. 0.24

B. 600

C. 1

D. 3.97

1848. _________________ is the separation technique used for desalination of sea water ?
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A. Reverse osmosis

B. Absorption

C. Thermal diffusion

D. Adsorption

1849. Water entrained by circulating air in cooling towers is termed as____________________?
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A. Drift

B. Blow down

C. None of these

D. Vapor load

1850. Corresponding to Nusselt number in heat transfer, the dimensionless group in mass transfer is the ________________ number?
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A. Schmidt

B. Sherwood

C. Stanton

D. Peclet

1851. In a gas-liquid absorption column, for obtaining the maximum absorption efficiency____________________?
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A. Liquid stream should be distributed uniformly

B. Gas stream should be distributed uniformly

C. Both gas as well as liquid streams should be distributed uniformly

D. By passing should be completely avoided

E. wer: Option C

1852. Pick out the correct statement ?
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A. ms</strong>

B. Vegetable oils are classified as drying, non-drying and semi drying oils depending upon their

C. ty acids content

D. All vegetable oils except coconut oil, contains fatty acids having more than sixteen carbon

E. There is no difference between a fat and an oil so far as its physical properties are concerned

F. A fat is converted into oil by its hydrogenation

1853. Degree of freedom for leaching and solvent extraction process is_____________________?
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A. 1

B. 0

C. 3

D. 2

1854. If f is defined as above, then which of the following applies to a feed at dew point ?
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A. 0 < f < 1

B. f = 1

C. f 1

1855. With the lowering of equilibrium pressure, at a given temperature, the amount of adsorbate on the adsorbent ?
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A. Decreases

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

C. Remain same

D. Increases

1856. Which of the following has the same dimension as mass diffusivity ?
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A. Momentum flux

B. Kinematic viscosity

C. Thermal diffusivity

D. Both B. and C.
1857. Which of the following gas-liquid contacting devices incurs the least pressure drop for a particular duty ?
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A. Wetted wall tower

B. Bubble cap tower

C. Grid tray tower

D. Perforated tray tower

1858. Sodium bicarbonate is produced during soda ash manufacture using a _______________ tower?
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A. None of these

B. Plate

C. Baffle

D. Packed

1859. The equilibrium liquid composition compared to the vapor composition in case of________________?
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A. Either more or less; depends on the system

B. Less

C. More

D. Same

E. otropic mixture is

1860. The percentage humidity is less than the relative humidity only at __________________ percent humidity?
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A. Zero

B. Hundred

C. Both zero and hundred

D. None of these