Mass Transfer MCQs

Question 1

When a multistage tray tower uses a minimum reflux ratio, it implies

Accepted Answer

Infinite trays and maximum reboiler heat load

Answer

Infinite trays and minimum reboiler heat load

Answer

Minimum trays and minimum reboiler heat load

Answer

Minimum trays and maximum reboiler heat load

Question 2

Bound moisture is that liquid which exerts an equilibrium vapor pressure __________ that of the pure liquid at the given temperature.

Accepted Answer

Less than

Answer

More than

Answer

Equal to

Answer

Either A or B; depends on the solid

Question 3

With increase in absolute humidity, the dew point of an unsaturated mixture of air and water vapor (at constant pressure and temperature)

Accepted Answer

Increases

Answer

Remains unchanged

Answer

Decreases

Answer

Decreases linearly

Question 4

__________ extractor uses centrifugal force for separating the two phases.

Accepted Answer

Podbielniak

Answer

Treybal

Answer

Schiebel

Answer

None of these

Question 5

Pick out the wrong statement.

Accepted Answer

Mass transfer co-efficient does not account for gase-liquid diffusion

Answer

Diffusion co-efficient and mass transfer co-efficient are not same in any mass transfer operation

Answer

Contacting cold vapor-gas mixture with hot liquid exemplifies humidification process

Answer

Contacting cold liquid with warm vapor-gas mixture exemplifies dehumidification process

Question 6

Which of the following same diameter columns gives lowest pressure drop per unit height?

Accepted Answer

Packed column (stacked)

Answer

Bubble-cap column

Answer

Sieve-plate column

Answer

Randomly packed column

Question 7

The minimum number of theoretical plates is required for achieving a given separation in distillation column with

Accepted Answer

Total reflux

Answer

No reflux

Answer

Zero reflux ratio

Answer

Minimum reflux ratio

Question 8

Wetted wall tower experiment determines the

Accepted Answer

Mass transfer co-efficient

Answer

Molal diffusivity

Answer

Volumetric co-efficient

Answer

None of these

Question 9

During the constant rate period of drying of a solid,

Accepted Answer

Surface evaporation of unbound moisture occurs

Answer

Increased air humidity decreases the rate of drying

Answer

Increasing the air temperature decreases the drying rate

Answer

None of these