Top 550+ Solved Mass Transfer MCQ Questions Answer
Q. Removal of __________ exemplifies an adsorption unit operation.
a. Uranium from its ore
b. Water from petrol
c. Ammonia from coke oven gas
d. Mustard oil from mustard seed
Q. Use of packed towers for distillation is generally limited to the
a. Small sizes
b. Multi-component distillation
c. High pressure operation
d. Vacuum distillation
Q. Dimension of mass diffusivity is the same as that of
a. Kinematic viscosity
b. Dynamic viscosity
c. Surface tension
d. Pressure
Q. Pick out the wrong statement
a. A horizontal line on the humidity chart indicates the temperature changes at constant molal humidity
b. When water is cooled from 80 to 70°C by exposure to the air with a wet bulb temperature of 60°C, then both the approach & the range would be 10°C
c. For unsaturated air-water vapor mixture at atmospheric conditions, the wet bulb temperature & adiabatic cooling lines are the same
d. Relative saturation of unsaturated mixture of water vapor & air cannot be increased by either reducing the mixture temperature or by increasing the total pressure
Q. Laboratory determination of the diffusivity of vapor is done by __________ method.
a. Wetted wall column
b. Gilliland's
c. Winkelmann's
d. Wike's
Q. The relation among various mass transfer co-efficients (M.T.C) for ideal gases is given by (where, Kc & Km are M.T.C. for equimolar counter diffusion with concentration & mole fraction respectively as the driving force. and, Kp= M.T.C. for diffusion of a gas through a stagnant inert gas with pressure as driving force.)
a. Kc = Kp = Km
b. Kc = Kp/RT = Km . RT/P
c. Kc = Kp . RT = Km . RT/p
d. None of these
Q. Pick out the wrong statement:
a. Change in barometric pressure does not affect the relative humidity
b. In case of a packed tower, the operating velocity is about half of the flooding velocity, generally
c. 'Elution' means the desorption of the adsorbed solute by a solvent
d. The equilibrium moisture content of the solid can be reduced by increasing the absolute humidity
Q. The temperature of water cooled in cooling tower is always __________ temperature of entering air.
a. More than the wet bulb
b. Less than the wet bulb
c. Equal to the wet bulb
d. Equal to the dry bulb
Q. Design calculation for multiple component distillation is done by
a. Ponchon-Savarit method
b. McCabe-Thiele method
c. Enthalpy concentration method
d. Tray to tray calculations
Q. Absorption (liquid-gas system) with evolution of heat as compared to isothermal absorption results in
a. Decreased solute solubility
b. Large minimum liquid to gas (L/G) ratio
c. Large number of trays
d. All (A), (B) and (C)
Q. Drying of a wet solid under constant drying conditions means the exposure of the wet solid to the air of constant
a. Humidity
b. Velocity
c. Temperature
d. All (A), (B) & (C)
Q. In liquid extraction, if the selectivity is unity, then
a. Separation of the constituents is the most effective
b. No separation will occur
c. Amount of solvent required will be minimum
d. Solvent flow rate should be very low