Top 550+ Solved Mass Transfer MCQ Questions Answer
Q. Mass transfer co-efficient varies as DAB0.5, according to the __________ theory.
a. Film
b. Surface renewal
c. Penetration
d. None of these
Q. The suitable evaporator for concentration of foaming liquids is a __________ evaporator.
a. Long tube
b. Short tube
c. Vacuum
d. Falling film
Q. In stripping section of continuous distillation column, the
a. Liquid is stripped of high boiler
b. Liquid is enriched with high boiler
c. Vapour is stripped of low boiler
d. None of these
Q. An aqueous solution of methanol is to be distilled in a tray column. High pressure steam is available as a source of heat. For a given reflux ratio and overhead composition, two options are being explored; (i) a reboiler is used and (ii) no reboiler is used but steam is fed directly to the bottom of the column. As compared to option (i), in option (ii)
a. Less number of trays are required
b. Composition of the residue remains unchanged
c. More number of trays are required but the residue composition remains unchanged
d. More number of trays are required and the residue composition is more dilute in methanol
Q. NSc/NPr is called the
a. Psychrometric ratio
b. Lewis number
c. Sherwood number
d. Stanton number
Q. At constant pressure, with increase of temperature, the dew point will
a. Increase
b. Decrease
c. Remain unchanged
d. Increase/decrease; depends on the temperature
Q. Pick out the correct statement.
a. Dialysis process is used for the production of fresh water from brine
b. Electrodialysis is used in the manufacture of NaOH
c. Electrodialysis is used for the refining/purification of petrol
d. Both (B) and (C)
Q. The percentage humidity is less than the relative humidity only at __________ percent humidity.
a. Zero
b. Hundred
c. Both zero and hundred
d. None of these
Q. 'ADDUCTS' and 'CLATHRATES' are used in case of
a. Extractive distillation
b. Crystallisation
c. Absorption
d. None of these
Q. __________ is concerned with the adsorption equilibria.
a. Fick's law
b. Gibb's equation
c. Freundlich equation
d. None of these
Q. In most of the vacuum crystalliser, vacuum is generally produced by means of a
a. Suction pump
b. Compressed air jet
c. Steam jet ejector with a barometric condenser
d. None of these
Q. In a distillation column, with increase in the reflux ratio, the heat removed in the cooler
a. Increases
b. Decreases
c. Remains unaffected
d. And the heat required in reboiler decreases
Q. The feed to fractionating column is changed from saturated vapour to saturated liquid. If the separation and reflux ratio remains unchanged, the number of ideal stages will
a. Increase
b. Decrease
c. Remain same
d. Depend on saturated boiling point; may increase or decrease
Q. During constant rate drying period, vaporisation rate per unit drying surface area
a. Decreases with time
b. Increases with time
c. Does not change with time
d. Does not affect the moisture content of the wet solid
Q. A coalescer in a mixer-settler liquid-liquid extraction column
a. Comprises of thin bed of substances of extended surface having high porosity
b. Helps in increasing the bubble size entering the settler
c. Helps in increasing the settling rate of the bubbles
d. All 'a', 'b', & 'c'