chemical engineering MCQs – Page 97

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 Review each marked answer and report any item that may be outdated or unclear.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
1921. The humid volume may be increased by increasing the____________________?
comments icon0

A. Temperature at constant humidity

B. Humidity at constant temperature

C. Both A. and B.

D. Neither A. nor B.

1922. Plate efficiency_______________________?
comments icon0

A. Increases due to weeping and dumping of liquid

B. Is a function of the mass transfer between liquid and vapour

C. Increases due to foaming

D. Increases due to liquid entrainment

1923. Leaching of uranium ore and gold ore is done in________________________?
comments icon0

A. None of these

B. Bollman extractor

C. Centrifugal extractor

D. Pachuca tanks
1924. With increase in temperature, the solubility of gases in liquids, at fixed pressure____________________?
comments icon0

A. Remain same

B. Increases

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

D. Decreases
1925. Which of the following is considered equivalent to one theoretical stage in Mc-Cabe Thieles method ?
comments icon0

A. Partial condenser

B. Total condenser

C. Reboiler

D. Both B. and C
1926. Diameter of raschig rings used in packed tower in industry is normally around _____________________ inches?
comments icon0
A. 2

B. 8

C. 12

D. 18

1927. The expression, y(1 x)/x(1 y) is for_____________________?
comments icon0

A. Selectivity

B. Absorption factor

C. Relative volatility

D. Murphree efficiency

1928. Surface renewal model of mass transfer was enunciated by___________________?
comments icon0

A. Stefan

B. Fick

C. Toor and Marcello

D. Danckwerts
1929. Can the efficiency of a plate in the distillation tower be greater than 100% ?
comments icon0

A. Yes; if the reflux ratio is maximum

B. Yes

C. Normally not; but is possible if infinite number of plates are put

D. Never
1930. When both the fluids flow concurrently in an absorber, the slope of the operating line is____________________?
comments icon0

A. 1

B. -ve

C. #NAME?

D. -1

1931. Molecular diffusivity of a liquid__________________?
comments icon0

A. Decreases with temperature

B. May increase or decrease with temperature

C. Increases with temperature

D. Is independent of temperature

1932. Rose oil is extracted from rose leaves using ____________ distillation?
comments icon0

A. Low pressure

B. Extractive

C. Steam

D. High pressure

1933. In liquid extraction, if the selectivity is unity, then___________________?
comments icon0

A. Solvent flow rate should be very low

B. Amount of solvent required will be minimum

C. Separation of the constituents is the most effective

D. No separation will occur
1934. Measurement of the interfacial area of mass transfer is achieved easily & accurately in case of a ________________ column?
comments icon0

A. Spray

B. Wetted wall

C. Packed

D. Bubble cap plate

1935. Weeping in a distillation column_____________________?
comments icon0
A. Results due to very low gas velocity

B. Increases tray efficiency

C. Provides large interfacial surface for mass transfer

D. Results due to very high gas velocity

1936. High pressure at the bottom of a distillation tower handling heat sensitive materials results in _____________________?
comments icon0
A. Thermal decomposition of bottoms

B. Erosion of the tower

C. Very efficient operation

D. Increased relative volatility

1937. In which of the following unit operations, the selectivity is an important parameter ?
comments icon0

A. Distillation

B. Solvent extraction

C. Absorption

D. None of these

1938. In case of liquids, the binary diffusivity is proportional to (where, T = temperature) _____________________?
comments icon0

A. ?T

B. 1/T

C. T2

D. T
1939. Fractional solvent extraction______________________?
comments icon0

A. Employs only one solvent

B. Results in low interfacial tension

C. None of these

D. Employs two solvents
1940. Advantage of continuous drying over batch drying is that the_____________________?
comments icon0
A. All A , B. & C.

B. Drying cost per unit weight of dried product is less

C. Product with more uniform moisture content is produced

D. Equipment size required is smaller