Mass Transfer MCQs

Question 1

In extractive distillation, solvent is

Accepted Answer

Added to alter the relative volatility of the mixture

Answer

Of high volatility

Answer

Present in overhead stream

Answer

Of high viscosity to give high tray efficiency

Question 2

Hypersorption refers to a __________ process.

Accepted Answer

Moving bed adsorption

Answer

Fixed bed absorption

Answer

Moving bed absorption

Answer

Fixed bed adsorption

Question 3

The wet and dry bulb temperature for a vapour-gas mixture are 25°C and 30°C respectively. If the mixture is heated to 45°C at constant pressure, the wet bulb temperature will be __________ °C.

Accepted Answer

> 25

Answer

25

Answer

< 25

Answer

- 25

Question 4

Large quantity of silica gel is normally dried in a __________ dryer.

Accepted Answer

Through circulation

Answer

Freeze

Answer

Rotary vacuum

Answer

Tray

Question 5

Pick out the wrong statement pertaining to the cooling towers.

Accepted Answer

Effectiveness of a mechanical draft cooling tower is reduced with increase in air wet-bulb temperature

Answer

In case of induced draft cooling tower, the fan is placed at the top of the tower

Answer

Effectiveness of forced draft cooling tower is reduced by the recirculation of the humid and hot discharged air

Answer

A natural draft cooling tower is recommended to be used, when the air humidity is low and air temperature is also low

Question 6

Which of the following solutions will follow Raoult's law most closely?

Accepted Answer

A solution of benzene, toluene and oxylene

Answer

35% solution of camphor in water

Answer

35% solution of NH 3 in water

Answer

A solution of polar organic compounds (not of homologs of a series)

Question 7

The overall mass transfer co-efficient for the absorption of SO 2 in air with dilute NaOH solution can be increased substantially by

Accepted Answer

Increasing the gas film co-efficient

Answer

Increasing the liquid film co-efficient

Answer

Increasing the total pressure

Answer

Decreasing the total pressure

Question 8

Selectivity of the solvent used in solvent extraction should be

Accepted Answer

> 1

Answer

1

Answer

< 1

Answer

0

Question 9

Hydrogenation of oil is carried out in a/an __________ in Vanaspati manufacturing plant.

Accepted Answer

Agitated vessel

Answer

Sieve tray column

Answer

Bubble cap column

Answer

Packed tower