Mass Transfer MCQs

Question 1

If a two phase system is in physical equilibrium; then it means that, the

Accepted Answer

All of the above

Answer

Escaping tendency of each component from the liquid phase to the vapor phase is exactly equal to that from vapor phase to liquid phase

Answer

Temperature of the liquid phase is equal to that of the vapor phase

Answer

Total pressure throughout the liquid phase is equal to that throughout the vapor phase

Question 2

Mass transfer co-efficient is directly proportional to DAB0.5, according to __________ theory.

Accepted Answer

Penetration

Answer

Surface renewal

Answer

Film

Answer

None of these

Question 3

Which of the following provides maximum contact surface for a liquid-vapour system?

Accepted Answer

Packed tower

Answer

Bubble-cap plate column

Answer

Seive-plate column

Answer

Wetted wall column

Question 4

In distillation where q is defined as the moles of liquid flow in the stripping section per mole of feed introduced, for saturated liquid feed

Accepted Answer

q = 1

Answer

q > 1

Answer

q < 1

Answer

q = 0

Question 5

Pick out the wrong statement.

Accepted Answer

Heat removal load on cooler remains constant, even with increase of the reflux ratio in a distillation column

Answer

Different solids have different equilibrium moisture curves

Answer

Total condenser or reboiler is considered equivalent to one theoretical plate in McCabe-Thiele method of theoretical plate calculation for distillation column

Answer

Even a forced draft cooling tower can not cool water below the wet bulb temperature

Question 6

A slurry is to be dried to produce flaky solid. Which dryer would you recommend?

Accepted Answer

Spray dryer

Answer

Drum dryer

Answer

Rotary dryer

Answer

Dielectric dryer

Question 7

Channelling is most severe

Accepted Answer

In towers packed with stacked packing

Answer

In towers packed randomly with crushed solids

Answer

In dumped packing of regular units

Answer

At very high liquid flow rate

Question 8

CO2 can be absorbed by

Accepted Answer

Heated charcoal

Answer

Hot cupric oxide

Answer

Cold Ca(OH)2

Answer

Alumina

Question 9

Radioactive nuclear waste is treated in

Accepted Answer

Pulsed column extractor

Answer

Mixer-settler extractor

Answer

Rotating-disc contactor

Answer

Bollman extractor