Mass Transfer MCQs

Question 1

'ADDUCTS' and 'CLATHRATES' are used in case of

Accepted Answer

Crystallisation

Answer

Extractive distillation

Answer

Absorption

Answer

None of these

Question 2

For a single component absorber, the operating line is straight only when plotted in term of __________ units.

Accepted Answer

Mole ratio

Answer

Partial pressure

Answer

Mole fraction

Answer

None of these

Question 3

Unsaturated air (with dry bulb temperature and dew point being 35°C and 18°C respectively) is passed through a water spray chamber maintained at 15°C. The air will be cooled

Accepted Answer

And dehumidified with decrease in wet bulb temperature

Answer

And humidified

Answer

And dehumidified with increase in wet bulb temperature

Answer

At the same relative humidity

Question 4

Diameter to height ratio for a rashig ring is

Accepted Answer

1

Answer

0.5

Answer

2

Answer

8

Question 5

In the layout plan for a vacuum distillation unit, operating at 60 mm Hg, supported by a barometric condenser, the appropriate place for the location of vacuum drum for collecting the distillate will be

Accepted Answer

At ground level

Answer

2 metres above the ground

Answer

5 metres above ground

Answer

10 metres above ground

Question 6

Pick out the wrong statement.

Accepted Answer

The operating line lies above the equilibrium curve in case of a gas desorber

Answer

When the concentration difference for the mass transfer becomes zero at the bottom of the gas absorption tower, then the upper end of the operating line touches the equilibrium curve

Answer

The average distance between the operating line and equilibrium line is large, when the liquid-gas ratio is also large in case of a counter current gas absorption tower

Answer

With decrease in the liquid flow rate for a fixed gas flow rate, the slope of the operating line decreases, in case of gas absorption process

Question 7

Design calculation for multiple component distillation is done by

Accepted Answer

Tray to tray calculations

Answer

Ponchon-Savarit method

Answer

Mccabe-Thiele method

Answer

Enthalpy concentration method

Question 8

Which of the following is an undesirable property for an absorbing solvent?

Accepted Answer

None of these

Answer

Low vapour pressure

Answer

Low velocity

Answer

Low freezing point

Question 9

In liquid extraction, if the selectivity is unity, then

Accepted Answer

No separation will occur

Answer

Separation of the constituents is the most effective

Answer

Amount of solvent required will be minimum

Answer

Solvent flow rate should be very low