Practice Test: Question Set - 08
1. Which of the following is the correct ternary diagram for liquid-liquid extraction system comprising of one pair partly soluble (e.g. water-benzene-acetic acid in which A - diluent, B - solvent and C - solute)?
2. Pick out the wrong statement pertaining to the analogy between equations of heat and mass transfer operations.
- (A) Sherwood
number in mass transfer is analogous to Nusselt number in heat transfer
- (B) Prandtl number in
heat transfer is analogous to Schmidt number in mass transfer
- (C) Reynolds number in
mass transfer is analogous to Grashoff number in heat transfer
- (D) Reynolds number
remains the same in both heat and mass transfer
3. Plate efficiency in a distillation column is reduced due to the __________ of liquid.
- (A) Entrainment
- (B) Foaming
- (C) Weeping & dumping
- (D) All (a), (b) &
(c)
4. Pick out the wrong statement.
- (A) Mass transfer
co-efficient does not account for gas-liquid diffusion
- (B) Diffusion
co-efficient and mass transfer co-efficient are not same in any mass transfer
operation
- (C) Contacting cold
vapor-gas mixture with hot liquid exemplifies humidification process
- (D) Contacting
cold liquid with warm vapor-gas mixture exemplifies dehumidification process
5. Blowdown in a cooling tower
- (A) Means
discarding a small fraction of circulating water to prevent and limit the
concentration of salt and impurities
- (B) Increases the scale
forming tendencies of water
- (C) Is
undesirable
- (D) All (a), (b) &
(c)
6. Pick out the wrong statement.
- (A) In solvent
extraction, the distribution co-efficient should be as large as possible for
solvent economy
- (B) With increase in
pressure, the solubility of gases in solvent increases at a fixed temperature
- (C) Decrease in Murphree
plate efficiency is an indication of entrainment in distillation column
- (D) The capacity of a
distillation column is maximum at total reflux
7. Rayleigh's equation applies to __________ distillation.
- (A) Continuous
- (B) Steam
- (C) Differential
- (D) Flash
8. In extraction, as the temperature increases, the area of heterogeneity (area covered by binodal curve)
- (A) Decreases
- (B) Increases
- (C) Remains unchanged
- (D) None of these
9. In most of the mechanically agitated liquid-liquid extractors, baffles or horizontal compartmental plates are provided, which helps in
- (A) Reducing the axial
mixing
- (B) Increasing the rate
of extraction
- (C) Maintaining the
concentration difference between the two phases
- (D) All 'a', 'b' &
'c'
10. The interfacial area per unit volume of dispersion, in a gas-liquid contactor, for fractional hold up of gas = 0.1 and gas bubble diameter = 0.5 mm is given by (in m2/m3)
- (A) 500
- (B) 1200
- (C) 900
- (D) 800
11. The slope of 9-line is determined by the
- (A) Reflux ratio
- (B) Plate efficiency to
be achieved
- (C) Thermal condition of
the feed
- (D) Relative volatility
12. For a binary mixture with low relative volatility,
- (A) Use
steam distillation
- (B) Use
molecular distillation
- (C) Use
high pressure distillation
- (D) An
azeotrope may be formed during distillation
13. Freundlich equation applies to the adsorption of solute from
- (A) Dilute solutions, over
a small concentration range
- (B) Gaseous solutions at
high pressure
- (C) Concentrated
solutions
- (D) None of these
14. Pick out the wrong statement pertaining to the cooling towers.
- (A) In case of induced
draft cooling tower, the fan is placed at the top of the tower
- (B) Effectiveness of
forced draft cooling tower is reduced by the recirculation of the humid and hot
discharged air
- (C) A natural draft
cooling tower is recommended to be used, when the air humidity is low and air
temperature is also low
- (D) Effectiveness of a
mechanical draft cooling tower is reduced with increase in air wet-bulb
temperature
15. The Hatta number is important in
- (A) Multi-component
distillation
- (B) Binary distillation
- (C) Gas absorption without
chemical reaction
- (D) Gas absorption with
chemical reaction