Mass Transfer MCQs

Question 1

Rotary dryers cannot handle __________ materials.

Accepted Answer

Sticky

Answer

Free flowing

Answer

Dry

Answer

Grannular

Question 2

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

Accepted Answer

Mass transfer co-efficient

Answer

Thermal diffusivity

Answer

Kinematic viscosity

Answer

Volumetric diffusivity

Question 3

CO 2 can be absorbed by

Accepted Answer

Heated charcoal

Answer

Hot cupric oxide

Answer

Cold Ca(OH) 2

Answer

Alumina

Question 4

Gaseous diffusion co-efficient increases with increase in the

Accepted Answer

Temperature

Answer

Pressure

Answer

Both A & B

Answer

Neither A nor B

Question 5

At a given equilibrium pressure, with increase in temperature, the concentration of adsorbed gas on solid adsorbant

Accepted Answer

Decreases

Answer

Increases

Answer

Remains unchanged

Answer

Increases exponentially

Question 6

Pick out the wrong statement

Accepted Answer

Relative saturation of unsaturated mixture of water vapor & air can not be increased by either reducing the mixture temperature or by increasing the total pressure

Answer

A horizontal line on the humidity chart indicates the temperature changes at constant molal humidity

Answer

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

Answer

For unsaturated air-water vapor mixture at atmospheric conditions, the wet bulb temperature & adiabatic cooling lines are the same

Question 7

In which of the following unit operations, the selectivity is an important parameter?

Accepted Answer

Solvent extraction

Answer

Distillation

Answer

Absorption

Answer

None of these

Question 8

The main reason for dividing a tall packed tower into series of small towers is to

Accepted Answer

Avoid channeling

Answer

Minimise the overall pressure drop

Answer

Avoid flooding

Answer

Reduce liquid hold up

Question 9

Only small amount of evaporation of water produces large cooling effects because of its

Accepted Answer

Large latent heat

Answer

Low viscosity

Answer

Small latent heat

Answer

None of these