Mass Transfer MCQs

Question 1

With decrease in the throughput (compared with the design capacity) for a bubble cap distillation column, its efficiency

Accepted Answer

Increases

Answer

Decreases

Answer

Remains same

Answer

May increase or decrease ; depends on individual design

Question 2

(N Sh /N Re .N Sc ) is termed in mass transfer operation as the

Accepted Answer

Stanton number

Answer

Peclet number

Answer

Thermal diffusivity

Answer

Momentum diffusivity

Question 3

Dimension of mass diffusivity is the same as that of

Accepted Answer

Kinematic viscosity

Answer

Dynamic viscosity

Answer

Surface tension

Answer

Pressure

Question 4

Which of the following unit operations makes use of Thiele-Geddes equation?

Accepted Answer

Multicomponent distillation

Answer

Liquid-liquid extraction

Answer

Solid-liquid extraction

Answer

Multicomponent absorption with chemical reaction

Question 5

In case of liquids, the binary diffusivity is proportional to (where, T = temperature)

Accepted Answer

T

Answer

$$\sqrt {	ext{T}} $$

Answer

T 2

Answer

$$\frac{1}{{	ext{T}}}$$

Question 6

For a distillation column operating at minimum reflux, the

Accepted Answer

Number of plates required will be maximum

Answer

Concentration of liquid and vapour leaving a plate will be same

Answer

Reflux ratio will be maximum

Answer

None of these

Question 7

When the liquid over a plate is of uniform concentration, then

Accepted Answer

Murphree efficiency = point efficiency

Answer

Murphree efficiency > point efficiency

Answer

Murphree efficiency < point efficiency

Answer

Murphree efficiency ≠ point efficiency

Question 8

A packed tower compared to a plate tower for a particular mass transfer operation

Accepted Answer

Incurs smaller pressure drop

Answer

Allows installation of cooling coils

Answer

Is less costly when built in large sizes/diameters

Answer

Is more suitable, if suspended solids are present in fluid streams

Question 9

Pressure drop through plate tower as compared to that through packed tower, for the same duty will be

Accepted Answer

More

Answer

Less

Answer

Equal

Answer

Either A or B; depends on the packing height