261. Percentage saturation is __________ the relative saturation.
Always smaller than
Always greater than
Not related to
None of these
✅ The correct answer is option A.
Mass Transfer MCQs
262. During the constant rate period of drying of a solid,
Increased air humidity decreases the rate of drying
Increasing the air temperature decreases the drying rate
Surface evaporation of unbound moisture occurs
None of these
✅ The correct answer is option C.
263. A liquid mixture contains 30% o-xylene, 60% p-xylene and 10%. m-xylene (all percentages in w/w). Which of the following statements would be true in respect of this mixture?
The mixture exhibits an azeotrope at 101.3 kPa
The composition of the mixture, in percent by volume is: o-xylene 30, p-xylene 60. and m-xylene 10
The composition of the mixture in mole percent is: o-xylene 30, p-xylene 60 and m-xyoene 10
The mixture contain optical isomers
✅ The correct answer is option A.
264. In case of cooling towers, the ratio of the rates of heat and mass transfer is indicated by the __________ number.
Lewis
Grashoff
Sherwood
None of these
✅ The correct answer is option A.
265. Flash distillation is
Same as differential distillation
Used for multicomponent systems like crude refining
Same as simple distillation
Most useful for handling binary systems
✅ The correct answer is option B.
266. In a packed tower, the value of HETP equals HTUOG, when the equilibrium and the operating lines are (where, HETP = height equivalant to a theoretical plate HTUOG = overall gas phase height of a transfer unit)
Straight
Parallel
Both A & B
Neither A nor B
✅ The correct answer is option C.
267. Fenske-Underwood equation used for calculating the minimum number of theoretical plates in distillation column is valid for
Constant molal overflow
Total reflux
Constant relative volatility
All of the above
✅ The correct answer is option D.
268. Drying operation under vacuum is carried out to
Dry those materials which have very high unbound mositure content
Reduce drying temperature
Increase drying temperature
Dry materials having high bound moisture content
✅ The correct answer is option B.
270. Which of the following unit operations makes use of Thiele-Geddes equation?
Liquid-liquid extraction
Solid-liquid extraction
Multicomponent absorption with chemical reaction
Multicomponent distillation
✅ The correct answer is option D.