Mass Transfer

Question: For achieving rapid drying rate in a spray dryer, the diameter of the particles in the feed should be in the range of __________ microns (1 mm = 1000 microns).
[A].

1-5

[B].

10-60

[C].

200-300

[D].

> 500

Answer: Option B

Explanation:

No answer description available for this question.

Question: In steam distillation, the
[A].

temperature is 100°C.

[B].

temperature is more than 100° C.

[C].

product must be immiscible with water.

[D].

temperature is higher than the boiling point of either component.

Answer: Option C

Explanation:

No answer description available for this question.

Question: If the solubilities of different components (in a liquid-liquid extraction system) increase with rise in temperature, then the temperature above which they dissolve completely is known as the critical solution temperature (CST or consolute temperature). If solubilities increase with decrease in temperature, then CST is the temperature below which they dissolve completely. If a binary system has no critical solution temperature, it implies that
[A].

the system comprises of partially mis-cible liquids.

[B].

the system comprises of miscible liquids.

[C].

the system comprises of an azeotrope.

[D].

on heating, a vapor phase will appear ; while on cooling, a solid phase will appear.

Answer: Option D

Explanation:

No answer description available for this question.

Question: Molecular distillation is
[A].

high temperature distillation

[B].

for heat-sensitive materials

[C].

very low pressure distillation

[D].

both (b) and (c)

Answer: Option D

Explanation:

No answer description available for this question.

Question: Drying of a wet solid under constant drying conditions means the exposure of the wet solid to the air of constant
[A].

humidity

[B].

velocity

[C].

temperature

[D].

all (a), (b) & (c)

Answer: Option D

Explanation:

No answer description available for this question.

Question: In extractive distillation, solvent is
[A].

added to alter the relative volatility of the mixture.

[B].

of high volatility.

[C].

present in overhead stream.

[D].

of high viscosity to give high tray efficiency.

Answer: Option A

Explanation:

No answer description available for this question.

Question: A natural draft cooling tower is filled with wooden grids, which covers about __________ percent of the tower height.
[A].

10-15

[B].

30-40

[C].

70-80

[D].

90-100

Answer: Option A

Explanation:

No answer description available for this question.

Question: During drying operation, it is easier to remove the __________ moisture.
[A].

equilibrium

[B].

critical

[C].

unbound

[D].

bound

Answer: Option C

Explanation:

No answer description available for this question.

Question: Azeotropism for ethyl alcohol-water system disappears by
[A].

increasing temperature

[B].

decreasing pressure

[C].

increasing pressure

[D].

no means

Answer: Option B

Explanation:

No answer description available for this question.

Question: Alcohol is dehydrated using __________ distillation.
[A].

extractive

[B].

azeotropic

[C].

steam

[D].

molecular

Answer: Option B

Explanation:

No answer description available for this question.