Mass Transfer MCQs

Question 1

Which of the following adsorbent is used to decolourise yellow glycerine?

Accepted Answer

Activated carbon

Answer

Silica gel

Answer

Alumina

Answer

Fuller

Question 2

Mass transfer co-efficient is defined as

Accepted Answer

Co-efficient = flux/concentration difference

Answer

Flux = co-efficient/concentration difference

Answer

Flux = concentration difference/co-efficient

Answer

None of these

Question 3

To get high tray efficiency

Accepted Answer

Interfacial surface between liquid and gas phase should be large

Answer

Time of contact between the two phases should be less

Answer

Gas velocity should be very low

Answer

Liquid entrainment should be severe

Question 4

Which of the following can be calculated theoretically using steam table and Dalton's law of partial pressure; if the relative humidity and dry bulb temperature of moist air is known?

Accepted Answer

Wet bulb temperature

Answer

Dew point

Answer

Humidity ratio

Answer

None of these

Question 5

A coalescer in a mixer-settler liquid-liquid extraction coloumn

Accepted Answer

All of the above

Answer

Comprises of thin bed of substances of extended surface having high porosity

Answer

Helps in increasing the bubble size entering the settler

Answer

Helps in increasing the settling rate of the bubbles

Question 6

Which of the following psychrometric processes is followed by water vapour laden unsaturated air, when it is passed through solid or liquid adsorbent?

Accepted Answer

Heating and dehumidification at almost constant wet bulb temperature

Answer

Cooling and dehumidification

Answer

Dehumidification with dry bulb temperature remaining constant

Answer

None of these

Question 7

The slope of the operating line for a single component co-current absorber when plotted in terms of mole ratio units is

Accepted Answer

-ve

Answer

0

Answer

∞

Answer

+ve

Question 8

Which of the following parameters remains constant during chemical dehumidification?

Accepted Answer

Dry bulb temperature

Answer

Partial pressure of vapour

Answer

Wet bulb temperature

Answer

None of these

Question 9

Flooding results in

Accepted Answer

Low tray efficiency

Answer

High tray efficiency

Answer

High gas velocity

Answer

Good contact between the fluids