Top 550+ Solved Mass Transfer MCQ Questions Answer
Q. For __________ drying, the effects of velocity, temperature and humidity of the gas and thethickness of the solid are the same.
a. Unsaturated surface
b. Constant rate
c. Both (A) and (B)
d. Neither (A) nor (B)
Q. In continuous distillation, the internal reflux ratio (Ri) and the external reflux ratio (Re) are related as
a. Ri = Re/(1 - Re)
b. Ri = (1 - Re)/Re
c. Ri = Re
d. Ri = Re/(1 + Re)
Q. Deaeration (removal of O2) of water is done by
a. Rectification
b. Absorption
c. Ion-exchange
d. Adsorption
Q. For the air water system under ambient conditions, the adiabatic saturation temperature and the wet bulb temperature are nearly equal, because
a. Water has a high latent heat of evaporation
b. Lewis number is close to unity
c. They are always equal under all circumstances
d. Solubility of the components of air in water is very small
Q. Dew point of a gas-vapour mixture
a. Increases with temperature rise
b. Decreases with temperature rise
c. Decreases with decrease in pressure
d. Increases with increase in pressure
Q. If moisture content of solid on dry basis is X, then the same on wet basis is
a. X/(X + 1)
b. X/(1 - X)
c. (1 + X)/X
d. (1 - X)/X
Q. __________ temperature is the steady state temperature attained by a small amount of liquid evaporating into a large quantity of unsaturated gas-vapor mixture.
a. Dry bulb
b. Wet bulb
c. Dew point
d. None of these
Q. In case of steam distillation, the steam leaving the liquid is not completely saturated with distillate vapour, because
a. Temperature is less
b. Total pressure is less
c. Mixing of steam with the material being vaporised is not so intimate as to result in equilibrium condition
d. Saturated steam is used for steam distillation
Q. Which of the following unit operations makes use of Thiele-Geddes equation?
a. Liquid-liquid extraction
b. Solid-liquid extraction
c. Multi-component absorption with chemical reaction
d. Multi-component distillation
Q. Gaseous diffusion co-efficient increases with increase in the
a. Pressure
b. Temperature
c. Both (A) & (B)
d. Neither (A) nor (B)
Q. Sides of equilateral-triangular co-ordinates (on which ternary liquid system is plotted)represent
a. A pure component
b. A binary mixture
c. A ternary mixture
d. Partially miscible ternary system
Q. The rate of mass transfer is not dependent upon the
a. Degree of dispersion of one fluid in the other
b. Interfacial surface exposed between the phases
c. Both (A) & (B)
d. None of these
Q. Air at a particular humidity is heated in a furnace. The new dew point
a. Decreases
b. Increases
c. Depends on the extent of heating
d. Remain unchanged
Q. The rate of solid-liquid extraction is limited by the
a. Phase change of the solute as it dissolves in the solvent
b. Diffusion of the solute through the solvent in the pores to the outside of the particle
c. Diffusion of the solute from the solution in contact with the particle to the main bulk of the solution
d. All 'a', 'b' & 'c'