Mass Transfer MCQs

Question 1

With increase in the concentration of the adsorbate, the integral heat of adsorption

Accepted Answer

Decreases

Answer

Increases

Answer

Remains unchanged

Answer

May increase or decrease ; depends on the type of adsorbate

Question 2

Fenske's equation for determining the minimum number of theoretical stages in distillation column holds good, when the

Accepted Answer

Relative volatility is reasonably constant

Answer

Mixture (to be separated) shows negative deviation from ideality

Answer

Mixture (to be separated) shows positive deviation from ideality

Answer

Multicomponent distillation is involved

Question 3

During bottling of cold drinks (e.g. Pepsi), the main resistance to mass transfer for the absorption of carbon dioxide in water lies in the

Accepted Answer

Liquid film

Answer

Gas film

Answer

Liquid-gas interface

Answer

None of these

Question 4

For experimental determination of mass transfer co-efficient by wetted wall tower, the mass transfer area is

Accepted Answer

Known

Answer

Calculated

Answer

Unknown

Answer

Not required

Question 5

When the solvent dissolves very little of solute, then

Accepted Answer

Large quantity of solvent is required to extract the solute

Answer

Solvent of low latent heat of vaporisation should be used

Answer

Solvent of low freezing point should be used

Answer

Very small quantity of solvent is required

Question 6

At a fixed pressure, the humidity depends upon the partial pressure of vapor in the mixture. Humidity of a vapour free gas is __________ percent.

Accepted Answer

0

Answer

100

Answer

50

Answer

Between 0 and 100

Question 7

High pressure at the bottom of a distillation tower handling heat sensitive materials results in

Accepted Answer

Thermal decomposition of bottoms

Answer

Increased relative volatility

Answer

Erosion of the tower

Answer

Very efficient operation

Question 8

Which of the following plays an important role in problems of simultaneous heat and mass transfer?

Accepted Answer

Lewis number

Answer

Schmidt number

Answer

Prandtl number

Answer

Sherwood number

Question 9

The term "approach" in a cooling tower refers to the difference in the temperature of the

Accepted Answer

Cold water leaving the tower and the wet bulb temperature of the surrounding air

Answer

Hot water entering the tower and the wet bulb temperature of the surrounding air

Answer

Hot water entering and the cooled water leaving the cooling tower

Answer

None of these