Top 550+ Solved Mass Transfer MCQ Questions Answer
Q. Cox chart is useful in the design of
a. Distillation column
b. Evaporator
c. Dryer
d. Crystalliser
Q. In a liquid-liquid extraction, 10 kg of a solution containing 2 kg of solute C and 8 kg of solvent A is brought into contact with 10 kg of solvent B. Solvent A and B are completely immiscible in each other whereas solute C is soluble in both the solvents. The extraction process attains equilibrium. The equilibrium relationship between the two phases is Y* = 0.9X, where Y* is the kg of C/kg of B and X is kg of C/kg of A. Choose the correct answer.
a. The entire amount of C is transferred to solvent B
b. Less than 2 kg but more than 1 kg of C is transferred to solvent B
c. Less than 1 kg of C is transferred to B
d. No amount of C is tr
Q. Pick out the wrong statement pertaining to leaching.
a. Fine solids cannot be leached in a Pachuca tank
b. Door classifier can be used for leaching of coarse solids
c. Vegetable seeds can be leached in either of Bollman extractor, Rotocel or Kennedy extractor
d. Very high temperature is not needed for the leaching of sugar beet
Q. Azeotropism for ethyl alcohol-water system disappears by
a. Increasing temperature
b. Decreasing pressure
c. Increasing pressure
d. No means
Q. Ordinary diffusion process is also called __________ diffusion.
a. Pressure
b. Thermal
c. Concentration
d. Forced
Q. The falling rate period in the drying of a solid is characterised by
a. Increase in rate of drying
b. Increasing temperatures both on the surface and within the solid
c. Decreasing temperatures
d. None of these
Q. Decoction refers to the use of solvent
a. At ambient temperature
b. At its boiling point
c. In its vapor form
d. None of these
Q. Out of the following gas-liquid contacting devices, for a given set of operating conditions, gas pressure drop is the least in __________ tower.
a. Wetted wall
b. Bubble cap
c. Perforated tray
d. Packed
Q. Pick out the correct statement.
a. For identical gas flow rates, less pressure drop occurs through a plate tower than through a packed tower
b. Plate column can handle greater liquid loads without flooding than packed column, but the liquid hold up is more in the case of plate column
c. For the same duty, plate columns weigh less than packed columns
d. All (A), (B) and (C)
Q. The solvent used in liquid-liquid extraction should have __________ less than one.
a. Selectivity
b. Distribution co-efficient
c. Both (A) and (B)
d. Neither (A) nor (B)
Q. Diffusion co-efficient generally depends upon the temperature, pressure & the nature of the components of the system. Its dimension is not the same as that of the
a. Mass transfer co-efficient
b. Thermal diffusivity
c. Kinematic viscosity
d. Volumetric diffusivity
Q. Pick out the wrong statement.
a. Different solids have different equilibrium moisture curves
b. Total condenser or reboiler is considered equivalent to one theoretical plate in McCabe-Thiele method of theoretical plate calculation for distillation column
c. Heat removal load on cooler remains constant, even with increase of the reflux ratio in a distillation column
d. Even a forced draft cooling tower cannot cool water below the wet bulb temperature
Q. Which of the following equipments is not used for liquid dispersion?
a. Wetted wall towers
b. Packed towers
c. Venturi scrubbers
d. Agitated vessels
Q. The rough value of diffusion co-efficient of water vapor into air at 25°C may be about __________ cm2/sec.
a. 0.25
b. 2.5
c. 1.25
d. 0.0025