151. NSc/NPr is called the
Psychrometric ratio
Lewis number
Sherwood number
Stantan number
✅ The correct answer is option B.
Mass Transfer MCQs
152. Ammonia present in the coke oven gas is removed by washing with
Caustic solution
Dilute ammoniacal liquor
Dilute HCl
Ethanolamine
✅ The correct answer is option B.
153. Bollman extractor
Is a static bed leaching equipment
Is used for extraction of oil from oilseed
Is a centrifugal extractor
Employs only counter-current extraction
✅ The correct answer is option B.
154. Small dia distillation column can be a
Packed column
Sieve tray
Bubble cap
Any of these
✅ The correct answer is option A.
155. McCabe-Thiele method of binary distillation does not assume that the
Sensible heat changes are negligible compared with latent heat changes
Molar latent heats of all components are equal
Heat of mixing is negligible
None of these
✅ The correct answer is option D.
156. In case of steam distillation, the steam leaving the liquid is not completely saturated with distillate vapour, because
Temperature is less
Total pressure is less
Mixing of steam with the material being vaporised is not so intimate as to result in equilibrium condition
Saturated steam is used for steam distillation
✅ The correct answer is option C.
157. For __________ drying, the effects of velocity, temperature and humidity of the gas and the thickness of the solid are the same.
Unsaturated surface
Constant rate
Both A & B
Neither A nor B
✅ The correct answer is option C.
158. With increase in the mass velocity of the gas, the rate of drying during the constant rate period __________ , if the conduction and radiation through the solid are negligible.
Increases
Decreases
Remains same
Increases linearly
✅ The correct answer is option A.
159. Pick out the wrong statement. Raoult’s law does not apply, when the
Size of component molecules are not equal
Attractive forces between like and unlike molecules in the solution are approximately equal
Component molecules are nonpolar
Chemical combination or molecular association between unlike molecules takes place in the formation of solution
✅ The correct answer is option C.
160. Leaching of coffee from coffee beans is done by
Hot water
Hexane
Lime water
Dilute H₂SO₄ (hot)
✅ The correct answer is option A.