Mass Transfer MCQs

Question 1

Pore size of the molecular seive 5A is __________ mm.

Accepted Answer

0.5

Answer

5

Answer

0.05

Answer

50

Question 2

Steady state equimolal counter diffusion occurs in case of

Accepted Answer

Binary phase distillation

Answer

Leaching

Answer

Absorption

Answer

Liquid-liquid extraction

Question 3

Very tall packed towers are divided into series of beds to

Accepted Answer

Avoid channelling

Answer

Reduce the overall pressure drop

Answer

Reduce liquid hold-up

Answer

Avoid flooding

Question 4

The suitable evaporator for concentration of foaming liquids is a __________ evaporator.

Accepted Answer

Long tube

Answer

Short tube

Answer

Vacuum

Answer

Falling film

Question 5

Weeping in a distillation column

Accepted Answer

Results due to very low gas velocity

Answer

Increases tray efficiency

Answer

Provides large interfacial surface for mass transfer

Answer

Results due to very high gas velocity

Question 6

Sides of equilateral-triangular co-ordinates (on which ternary liquid system is plotted) represent

Accepted Answer

A binary mixture

Answer

A pure component

Answer

A ternary mixture

Answer

Partially miscible ternary system

Question 7

Can a cooling tower cool water below the wet bulb temperature of inlet air?

Accepted Answer

No

Answer

Yes

Answer

Yes ; but height of cooling tower will be prohibitively high

Answer

Yes ; but the air flow rate should be excessively high

Question 8

Use of natural draft cooling tower is practised, when the air has low

Accepted Answer

Both A & B

Answer

Humidity

Answer

Temperature

Answer

Neither A nor B

Question 9

Agitator is provided in a crystalliser for

Accepted Answer

All of the above

Answer

Avoiding deposition on cooler surfaces

Answer

Formation of nuclei

Answer

Crystal growth