chemical engineering mass transfer MCQs – Page 33

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 Review each marked answer and report any item that may be outdated or unclear.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

641. Pick out the wrong statement ?
0

A. A horizontal line on the humidity chart indicates the temperature changes at constant molal

B. idity

C. When water is cooled from 80 to 70C by exposure to the air with a wet bulb temperature of

D. C, then both the approach & the range would be 10C

E. For unsaturated air-water vapor mixture at atmospheric conditions, the wet bulb temperature

F. p; adiabatic cooling lines are the same

642. Gaseous diffusion co-efficient increases with increase in the_____________________?
0

A. Pressure

B. Temperature

C. Both A. & B.

D. Neither A. nor B.

643. Corresponding to Prandtl number in heat transfer, the dimensionless group in mass transfer is the _______________ number?
0

A. Sherwood

B. Schmidt

C. Peclet

D. Stanton

644. In an interphase mass transfer process, the lesser the solubility of a given solute in a liquid, the higher are the chances that the transfer process will be_________________?
0

A. Driven by a non-linear driving force

B. Liquid phase resistance-controlled

C. Impossible

D. Gas phase resistance controlled

645. When the temperature and humidity of air is low, we usually use _______________ draft cooling tower?
0

A. Induced

B. None of these

C. Natural

D. Forced

646. Which of the following remains constant during sensible cooling process ?
0

A. Specific humidity

B. Partial pressure of vapour

C. Both A. and B.

D. Neither A. nor B.

647. For absorbers, high pressure drop results in___________________?
0

A. Decreased efficiency

B. Better gas liquid contact

C. Increased efficiency

D. High operating cost

648. Fenske equation determines the __________________?
0

A. Maximum number of ideal plates

B. Minimum number of theoretical plates

C. Height of the distillation column

D. Optimum reflux ratio

649. Make up water is supplied during cooling tower operation to compensate for water losses due to______________________?
0

A. All A., B. & C.

B. Evaporation

C. Entrainment

D. Blowdown

650. Pick out the wrong statement ?
0

A. Elutriation process refers to when the soluble material is largely concentrated on the surface of

B. ther

C. Cellulose acetate membranes are used in dialysis process

D. insoluble solid and is simply washed off by the solvent

E. Cascade means a group of stages interconnected so that various streams flow from one to

F. Zirconia probe is used for the humidity measurement

651. When adsorption hysteresis is observed, the desorption equilibrium pressure is _________________ that obtained by adsorption?
0

A. Always higher than

B. Same as

C. Dependent on the system; can be either lower or higher than

D. Always lower than

652. Berl saddle made of carbon cannot be used for ___________________?
0

A. Oxidising atmosphere

B. Alkalis

C. H2SO4

D. SO2

653. In case of gases, the binary diffusivity is proportional to (where, P = pressure) ?
0

A. 1/P

B. 1/?P

C. ?P

D. P

654. In saturated gas, the__________________?
0

A. Vapour is in equilibrium with the liquid at the room temperature

B. None of these

C. Partial pressure of vapour equals the vapour pressure of the liquid at room temperature

D. Vapour is in equilibrium with the liquid at the gas temperature

655. Pick out the wrong statement?
0

A. Change in barometric pressure does not affect the relative humidity

B. idity</strong>

C. erally

D. In case of a packed tower, the operating velocity is about half of the flooding velocity,

E. Elution means the desorption of the adsorbed solute by a solvent

F. The equilibrium moisture content of the solid can be reduced by increasing the absolute

656. Pick out the wrong statement pertaining to the cooling towers ?
0

A. In case of induced draft cooling tower, the fan is placed at the top of the tower

B. A natural draft cooling tower is recommended to be used, when the air humidity is low and air

C. perature</strong>

D. Effectiveness of forced draft cooling tower is reduced by the recirculation of the humid and

E. Effectiveness of a mechanical draft cooling tower is reduced with increase in air wet-bulb

F. discharged air

657. Which of the following adsorbent is used in the refining of sugar?
0

A. Silica gel

B. Wood charcoal

C. Activated clay

D. Bone charcoal

658. In extractive distillation, solvent is_____________________?
0

A. Present in overhead stream

B. Of high volatility

C. Added to alter the relative volatility of the mixture

D. Of high viscosity to give high tray efficiency

659. For which of the following unit operations, Lewis number is of significance ?
0

A. Humidification

B. Binary distillation

C. Gas absorption

D. Adsorption

660. Raoults law applies to the___________________?
0

A. Non-volatile solute

B. Solvents

C. Non-ideal solution only

D. All liquid solutions

Previous Next

Showing 641 to 660 of 697 mcqs