381. The binary diffusivity in gases and liquids vary respectively as
T3/2 and T
T and T3/2
√T and T3/2
T3/2 and √T
✅ The correct answer is option A.
Mass Transfer MCQs
382. In continuous distillation, the internal reflux ratio (Ri) and the external reflux ratio (Re) are related as
Ri = Re/(1 – Re)
Ri = (1 – Re)/Re
Ri = Re
Ri = Re/(1 + Re)
✅ The correct answer is option D.
383. Water-ethyl alcohal solution can be concentrated (in respect of alcohal concentration) by __________ distillation.
Atmospheric
Vacuum
High pressure
None of these
✅ The correct answer is option B.
384. The vapour pressure exerted by the moisture contained in a wet solid depends upon the
Nature of the moisture
Temperature
Nature of the solid
All of the above
✅ The correct answer is option D.
385. Which of the following quantities need not be fixed before starting the design of a co-current absorber?
Heat gain or loss
Flow rate of entering liquid
Flow rate of gas
None of these
✅ The correct answer is option B.
386. Which of the following mixtures does not form an azeotrope at atmosheric pressure?
Water-alcohol
Methyl alcohol-acetone
Butyl acetate-water
None of these
✅ The correct answer is option D.
387. Rayleigh’s equation applies to __________ distillation.
Continuous
Steam
Differential
Flash
✅ The correct answer is option C.
388. The humid volume may be increased by increasing the
Temperature at constant humidity
Humidity at constant temperature
Both A & B
Neither A nor B
✅ The correct answer is option C.
389. Heat load in a cooling tower
Means the amount of heat thrown away (KCal/hr.) by the cooling tower
Is equal to the number of kg, of water circulated times the cooling range
Both A & B
Neither A nor B
✅ The correct answer is option C.
390. Low viscosity absorbent is preferred for reasons of
Rapid absorption rates and good heat transfer characteristics
Improved flooding characteristics
Low pressure drop on pumping
All of the above
✅ The correct answer is option D.