chemical engineering mass transfer MCQs – Page 20

Practise multiple-choice questions from chemical engineering mass transfer for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

chemical engineering mass transfer Mcqs
381. With lapse of time, the overhead composition of light component in case of batch distillation with constant reflux__________________?
comments icon0

A. Increases

B. Remain same

C. May increase or decrease; depends on system

D. Decreases
382. The most economical range of absorption factor is____________________?
comments icon0

A. 0 to 3

B. 5 to 15

C. 1.25 to 2

D. 0 to 0.5

383. The amount of steam required per unit quantity of distillate in case of steam distillation will be reduced by __________________?
comments icon0

A. Raising the temperature

B. Lowering the total pressure

C. Both A. and B.

D. Neither A. nor B.

384. As complete saturation of an adsorbent is approached, the differential heat of adsrop-tion approaches ____________________?
comments icon0
A. That of normal condensation

B. None of these

C. Zero

D. Integral heat of adsorption

385. ______________ column is preferred to be used, when a high liquid hold up is required in a reactor for gas-liquid reaction ?
comments icon0

A. Packed

B. Bubble

C. Spray

D. Tray

386. The adiabatic saturation curve for a vapour-gas mixture is__________________?
comments icon0

A. None of these

B. Slightly concave upward

C. Straight line

D. Slightly concave downward

387. The recovery of penicillin from the acidified fermentation broth is done by__________________?
comments icon0

A. Distillation

B. Evaporation

C. Absorption

D. Liquid extraction
388. The relative saturation of an unsaturated mixture of gas and vapor is independent of the___________________?
comments icon0
A. None of these

B. Temperature of the mixture

C. Composition of the mixture

D. Nature of the vapor

389. Which of the following is not a continuous drier ?
comments icon0

A. Spray drier

B. Drum drier

C. Tunnel drier

D. Tray drier
390. With increase in the concentration of the adsorbate, the integral heat of adsorption____________________?
comments icon0

A. May increase or decrease; depends on the type of adsorbate

B. Remains unchanged

C. Decreases

D. Increases

391. Wet bulb and dry bulb temperatures becomes identical at _______________ percent saturation curve?
comments icon0

A. None of these

B. 100

C. 50

D. 78

392. A coalescer in a mixer-settler liquid-liquid extraction column______________________?
comments icon0

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

B. All a, b, & c

C. Helps in increasing the bubble size entering the settler

D. Helps in increasing the settling rate of the bubbles

393. Out of the following gas-liquid contacting devices, for a given set of operating conditions, gas pressure drop is the least in ______________ tower?
comments icon0

A. Packed

B. Wetted wall

C. Perforated tray

D. Bubble cap

394. NSc/NPr is called the______________________?
comments icon0

A. Sherwood number

B. Stanton number

C. Lewis number

D. Psychrometric ratio

395. Mass transfer co-efficient varies as DAB 0.5, according to the _______________ theory?
comments icon0

A. Film

B. Surface renewal

C. None of these

D. Penetration

396. Compound A is extracted from a solution of A + B into a pure solvent S. A Co-current unit is used for the liquid-liquid extraction. The inlet rate of the solution containing A is 200 moles of B/hr.m2 and the solvent flow, rate is 400 moles of S/m2. hr. The equilibrium data is represented by Y = 3X2 , where Y is in moles of a A/moles of B and X is in moles A/moles of S. The maximum percentage extraction achieved in the unit is_________________________?
comments icon0

A. 70%

B. 50%

C. 25%

D. 90%

397. Batch tray dryers suffers from the disadvantage of______________________?
comments icon0

A. High maintenance cost

B. High labour cost & low heat economy

C. Non-uniform & low production rate

D. All a, b & c

398. In case of an ideal solution, the total vapor pressure varies ______________ with the composition expressed as mole fraction?
comments icon0

A. Exponentially

B. Inversely

C. None of these

D. Linearly
399. The equilibrium liquid composition compared to the vapor composition in case of________________?
comments icon0

A. More

B. Either more or less; depends on the system

C. Same

D. Less

E. otropic mixture is

400. When the psychometric ratio is ______________ then the adiabatic saturation temperature and wet bulb temperature becomes equal?
comments icon0

A. 1

B. ?

C. 1