471. Desulphurisation of petrol is done in a
Bollman extractor
Rotating disc extractor
Packed extraction column
Plate type extraction column
✅ The correct answer is option B.
Mass Transfer MCQs
472. The amount of steam required per unit quantity of distillate in case of steam distillation will be reduced by
Raising the temperature
Lowering the total pressure
Both A & B
Neither A nor B
✅ The correct answer is option C.
473. In gas-liquid contact operation, the number of ideal stages, N = (xa – xb)/(xb – x*b) . This is true when the stripping factor ‘S’ is
S > 1
S < 1
S = 1
S = ∞
✅ The correct answer is option A.
474. For a binary mixture with low relative volatility,
Use steam distillation
Use molecular distillation
Use high pressure distillation
An azeotrope may be formed during distillation
✅ The correct answer is option D.
475. __________ developed the film theory.
Higbie
Fick
Ergun
Levenspeil
✅ The correct answer is option A.
476. According to Chilton-Colburn analogy for mass transfer, NSt.NSc2/3 is equal to
F
F/2
2f
1/f
✅ The correct answer is option B.
477. Air initially at 101. 3 kPa and 40°C and with a relative humidity of 50%, is cooled at constant pressure to 30°C. The cooled air has a
Higher dew point
Higher absolute (specific) humidity
Higher relative humidity
Higher wet bulb temperature
✅ The correct answer is option C.
478. The wet and ‘dry bulb temperature for a vapour-gas mixture are 25°C and 30°C respectively. If the mixture is heated to 45°C at constant pressure, the wet bulb temperature will be __________ °C.
25
> 25
< 25
-25
✅ The correct answer is option B.
479. With lapse of time, the overhead composition of light component in case of batch distillation with constant reflux
Increases
Decreases
Remains same
May increase or decrease ; depends on system
✅ The correct answer is option B.
480. Use of raschig rings in place of crushed stones as packing in packed beds (other things being same)
Increases pressure drop, increases surface area
Increases pressure drop, decreases surface area
Decreases pressure drop, increases surface area
Decreases pressure drop, decreases surface area
✅ The correct answer is option C.