Category: Mass Transfer

A. 5
B. 9
C. 12
D. 28

The dimension of diffusivity is same as that of the
A. Density
B. Molal concentration
C. Kinematic viscosity
D. Velocity head

A. 2.0
B. 1.56
C. 1.0
D. 0.56

A. Mass transfer co-efficient does not account for gas-liquid diffusion
B. Diffusion co-efficient and mass transfer co-efficient are not same in any mass transfer
operation
C. Contacting cold vapor-gas mixture with hot liquid exemplifies humidification process
D. Contacting cold liquid with warm vapor-gas mixture exemplifies dehumidification process

A. Increase in flow rate
B. Sharp drop in pressure drop
C. Sharp rise in pressure drop
D. None of these

A. Always lower than
B. Always higher than
C. Same as
D. Dependent on the system; can be either lower or higher than

A. Spray dryer
B. Spouted bed dryer
C. Tunnel dryer
D. Pan open to atmosphere

A. The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are the same
for NSc = NPr= 1
B. 1 Nm3 of dry air is lighter than 1Nm3 of humid air
C. The Lewis number of a mixture is unity, when the thermal diffusivity is equal to the mass
diffusivity
D. An Azeotropic mixture of two liquids has boiling point higher than either of them, when it
shows negative deviation from Raoult’s Law

A. Partial condenser
B. Total condenser
C. Reboiler
D. Both B. and C

A. Solvent of low latent heat of vaporisation should be used
B. Solvent of low freezing point should be used
C. Large quantity of solvent is required to extract the solute
D. Very small quantity of solvent is required