Mass Transfer MCQs

Question 1

Absorption factor is defined as (where, S 1 = slope of the operating line S 2 = slope of the equilibrium curve)

Accepted Answer

$$\frac{{{{	ext{S}}_1}}}{{{{	ext{S}}_2}}}$$

Answer

$$\frac{{{{	ext{S}}_2}}}{{{{	ext{S}}_1}}}$$

Answer

S 1 - S 2

Answer

S 1 × S 2

Question 2

For a binary mixture with low relative volatility, continuous rectification to get pure products will require

Accepted Answer

High reflux ratio

Answer

Low reflux ratio

Answer

Less number of trays

Answer

Small cross-section column

Question 3

Pick out the wrong statement.

Accepted Answer

Dehydration of ethyl alcohol is most economically done by molecular distillation at very high vacuum

Answer

Critical moisture content is not a property of the material itself

Answer

A sharp increase in pressure drop gives an indication of the flooding in a distillation column

Answer

Separation of components is not possible in liquid extraction, if selectivity is unity

Question 4

To increase the absorption factor, (where, G = gas flow rate, S = solvent flow rate)

Accepted Answer

Increase 'S' and decrease 'G'

Answer

Increase both 'G' and 'S'

Answer

Decrease both 'G' and 'S'

Answer

Increase 'G' and decrease 'S'

Question 5

Pick out the system with minimum boiling azeotrope at 1 atm.

Accepted Answer

Ethyl alcohol-water

Answer

Benzene-toluene

Answer

Hydrochloric acid-water

Answer

All of the above

Question 6

Heat in BTU necessary to increase the temperature of 1 lb of gas and its accompanying vapour by 1°F is called the

Accepted Answer

Specific heat

Answer

Latent heat

Answer

Humid heat

Answer

Sensible heat

Question 7

Deairation (removal of O 2 ) of water is done by

Accepted Answer

Ion-exchange

Answer

Rectification

Answer

Absorption

Answer

Adsorption

Question 8

Rate of leaching increases with increasing

Accepted Answer

Temperature

Answer

Viscosity of solvent

Answer

Pressure

Answer

Size of the solid

Question 9

For the same system, if the same liquid used in an absorber is decreased, the tower height will

Accepted Answer

Increase

Answer

Decrease

Answer

Remain unaffected

Answer

Decrease or increase ; depends on the type of liquid