The binary diffusivity in gases at atmospheric conditions is about ___________________?

According to the Fenske equation, what will be the minimum number of plates required in a distillation column to separate an equimolar binary mixture of components A and B into an overhead fraction containing 99 mol% A and a bottom fraction containing 98 mol% B ? Assume that relative volatility (αAB = 2) does not change appreciably in the column ?

A. 5

B. 9

C. 12

D. 28

During the constant rate period of drying of a solid ?

A. Increased air humidity decreases the rate of drying

B. Increasing the air temperature decreases the drying rate

C. Surface evaporation of unbound moisture occurs

D. None of these

Humidification involves mass transfer between a pure liquid phase and a fixed gas, which is___________________?

A. Insoluble in the liquid

B. Soluble in the liquid

C. Non-ideal in nature

D. At a fixed temperature

As the reflux ratio, in a continuous counter-current extraction is increased, the number of stages_______________________?

A. Increase

B. Decrease

C. Remain unchanged

D. Can either increase or decrease, depends on the system

Large scale drying of sugar is done in a _______________ dryer?

A. Spouted bed

B. Tray

C. Rotary

D. Truck