Mass Transfer MCQs

Question 1

In a packed absorption tower, if the equilibrium and operating lines are both straight lines, then the ratio, HETP/HTUOG __________ the absorption factor.

Accepted Answer

Both A and B

Answer

Increases with increase in

Answer

Is one at unity value of

Answer

Neither A nor B

Question 2

Operating velocity in a packed tower is usually __________ the flooding velocity.

Accepted Answer

Half

Answer

Twice

Answer

Equal to

Answer

More than

Question 3

Humid volume, at a given temperature is a/an __________ function of humidity.

Accepted Answer

Linear

Answer

Inverse

Answer

Exponential

Answer

Logarithmic

Question 4

When the temperature and humidity of air is low, we usually use __________ draft cooling tower.

Accepted Answer

Natural

Answer

Forced

Answer

Induced

Answer

None of these

Question 5

For the flow of gases through a capillary, with increase in temperature, the permeability __________ as per Knudsen law.

Accepted Answer

Increases

Answer

Decreases

Answer

Remains same

Answer

Either A or B; depends on the gas

Question 6

Extraction of pencillin employs a __________ extraction coloumn.

Accepted Answer

Centrifugal

Answer

Packed

Answer

Plate

Answer

None of these

Question 7

The relative volatility of a binary mixture at constant temperature __________ the total pressure.

Accepted Answer

Decreases with increase in

Answer

Increases with increase in

Answer

Is independent of

Answer

None of these

Question 8

For the case of flow of air past a wet bulb thermometer (air water vapour system), the approximate value of H2/ky.Cz is around

Accepted Answer

1

Answer

0.6

Answer

0.24

Answer

0.72

Question 9

The surface renewal frequency in Danckwerts model of mass transfer is given by (KL: mass transfer co-efficient)

Accepted Answer

$$\sqrt {{{	ext{K}}_{	ext{L}}}^2 \cdot {{	ext{D}}_{	ext{A}}}} $$

Answer

$${{	ext{K}}_{	ext{L}}}^2 \cdot {{	ext{D}}_{	ext{A}}}$$

Answer

$$\frac{{{{	ext{K}}_{	ext{L}}}^2}}{{{{	ext{D}}_{	ext{A}}}}}$$

Answer

$$\frac{{{{	ext{K}}_{	ext{L}}}}}{{{{	ext{D}}_{	ext{A}}}^2}}$$