1.5
-0.6
-1.5
0.6
✅ The correct answer is option C.
Mass Transfer MCQs
202. Pick out the correct relationship. (where, Ri = internal reflux ratio Ro = external reflux ratio. )
(1 + Ro) = Ro/Ri
(1 – Ro) = Ro/Ri
(1 + Ri) = Ro/Ri
(1 – Ri) = Ro/Ri
✅ The correct answer is option A.
203. In a counter-current liquid extractor
Both liquids flow at fixed rate
Both liquids can have any desired flow rate
Only one of the liquids may be pumped at any desired rate
Liquid’s flow rate depends upon the temperature and pressure
✅ The correct answer is option C.
204. Absorption accompanied with chemical reaction is exemplified by the absorption of
Ammonia in water
Benzol present in coke oven gas by wash oil
SO₂ in alkaline solution
All of the above
✅ The correct answer is option C.
205. A packed tower compared to a plate tower for a particular mass transfer operation
Incurs smaller pressure drop
Allows installation of cooling coils
Is less costly when built in large sizes/diameters
Is more suitable, if suspended solids are present in fluid streams
✅ The correct answer is option A.
206. According to the film theory of mass transfer, the mass transfer co-efficient is proportional to (where, D = molecular diffusivity)
D
D2
D0.5
1/D
✅ The correct answer is option A.
207. Separation of the isotopes of helium for scientific investigations is done by
Reverse osmosis
Thermal diffusion
Leaching
Solvent extraction
✅ The correct answer is option B.
208. With increase in pressure, the relative volatility for a binary system
Increases
Decreases
Remains same
Either A or B, depends on the system
✅ The correct answer is option B.
209. Channelling is most severe
In towers packed with stacked packing
In towers packed randomly with crushed solids
In dumped packing of regular units
At very high liquid flow rate
✅ The correct answer is option A.
210. During dehumidification of unsaturated air wet bulb temperature & partial pressure of vapor are not constant. However, during evaporative cooling process with recirculated water supply, the __________ remains constant.
Wet bulb temperature
Partial pressure of water vapor
Relative humidity
None of these
✅ The correct answer is option A.