Mass Transfer - Study Mode
[#571] The operating cost of a distillation column at minimum reflux ratio is
Correct Answer
(A) Minimum
[#572] Drying operation under vacuum is carried out to
Correct Answer
(B) Reduce drying temperature
[#573] Unit of molal diffusivity is
Correct Answer
(A) cm 2 /sec gm.mole
Explanation
Solution: Molal diffusivity (D m ) is a measure of how quickly a substance diffuses through a solvent when there is a concentration gradient between them. The unit of molal diffusivity is typically expressed in terms of square centimeters per second (cm 2 /s) multiplied by the number of grams (gm) of the solute per mole (mole) of the solute. So, the correct unit for molal diffusivity is cm 2 /sec gm.mole , which corresponds to option A.
[#574] __________ temperature is the steady state temperature attained by a small amount of liquid evaporating into a large quantity of unsaturated gas-vapor mixture.
Correct Answer
(B) Wet bulb
[#575] In a counter-current liquid extractor
Correct Answer
(C) Only one of the liquids may be pumped at any desired rate