Top 550+ Solved Mass Transfer MCQ Questions Answer
Q. The ratio of Murphree plate efficiency to point efficiency is 1 in a __________ flow model.
a. Plug
b. Perfectly mixed
c. Both (A) & (B)
d. Neither (A) nor (B)
Q. Plate efficiency
a. Is a function of the mass transfer between liquid and vapour
b. Increases due to foaming
c. Increases due to liquid entrainment
d. Increases due to weeping and dumping of liquid
Q. Weeping in a distillation column
a. Increases tray efficiency
b. Provides large interfacial surface for mass transfer
c. Results due to very high gas velocity
d. Results due to very low gas velocity
Q. The expression, y(1 - x)/x(1 - y) is for
a. Absorption factor
b. Relative volatility
c. Selectivity
d. Murphree efficiency
Q. The process employing desorption of the absorbed solute by a solvent is called
a. Elution
b. Osmosis
c. Reverse osmosis
d. Sublimation
Q. In McCabe-Thiele method, at infinite reflux ratio
a. Number of plates is maximum
b. Overhead product is maximum
c. Both the operating lines coincide with the diagram
d. None of these
Q. Plate towers are preferred to packed towers, when large temperature changes are involved, because of the reason that the
a. Packing may be crushed due to thermal expansion/contraction of the components of the equipments
b. Pressure drop in the equipment will be very high
c. Viscosity variation of the fluids may cause channelling/flooding
d. None of these
Q. Pick out the correct statement.
a. Higher hold up of the solid in the rotary dryer results in better exposure of the solids to the gas
b. The 'Hatta number' is important in problems involving gas absorption without chemical reaction
c. For a non-reacting binary mixture of ideal gases, the partial pressure distribution of both components is linear in the case of steady state equimolal counter-diffusion
d. Total reflux in case of distillation operation requires infinite number of plates for a binary system separation
Q. A binary mixture of benzene and cyclohexane is separated by
a. Flash vaporisation
b. Extractive distillation
c. Solvent extraction
d. Ordinary distillation
Q. Mass transfer co-efficient 'K' according to penetration theory varies with mass diffusivity as
a. D 0.5
b. D
c. 1/D
d. D 1.5
Q. The relative humidity of air decreases in-spite of an increase in the absolute humidity, when the
a. Temperature rises
b. Pressure rises
c. Temperature falls
d. Pressure falls
Q. The dew point of a saturated gas phase equals the __________ temperature.
a. Gas
b. Room
c. Wet bulb
d. None of these
Q. The amount of steam required per unit quantity of distillate in case of steam distillationwill be reduced by
a. Raising the temperature
b. Lowering the total pressure
c. Both (A) and (B)
d. Neither (A) nor (B)
Q. Priming in a distillation column
a. Results from very low gas velocity
b. Is desirable from point efficiency consideration
c. Is characterised by the presence of foam throughout the space between trays
d. Reduces the overall pressure drop