Practice Test: Question Set - 31
1. Equilibrium-moisture curves of different solids
- (A) Are
different
- (B) Are same
- (C) Depend on the
humidity of the gas
- (D) None of these
2. The caking of crystals can be prevented by
- (A) Maintaining high
critical humidity
- (B) Maintaining low
critical humidity
- (C) Coating the product
with inert material
- (D) Both (a) and (c)
3. In McCabe-Thiele method of theoretical plate calculation for a distillation column, the operating lines of stripping and rectifying sections coincide with the diagonal at __________ reflux.
- (A) Total
- (B) Minimum
- (C) Operating
- (D) Maximum permissible
4. Mass transfer co-efficient (K) and diffusivity (D) are related according to film theory as
- (A) K ∝ D
- (B) K ∝√D
- (C) K ∝ D1.5
- (D) K ∝ D2
5. Steady state equimolal counter diffusion occurs in case of
- (A) Leaching
- (B) Absorption
- (C) Binary phase
distillation
- (D) Liquid-liquid
extraction
6. On moving the feed line (q-line) from saturated liquid feed (vertical position) to saturated vapor feed (horizontal feed), if the slope of both the operating lines are to be increased, then it will result in
- (A) Greater degree of
separation with a fixed number of trays
- (B) Increased reboiler
load
- (C) Increased reflux
ratio
- (D) None of these
7. __________ is used as an 'entrainer' for the separation of acetic acid-water mixture by distillation.
- (A) Furfural
- (B) Benzol
- (C) Butyl acetate
- (D) Hexane
8. Mass transfer rate between two fluid phases does not necessarily depend on the __________ of the two phases.
- (A) Chemical properties
- (B) Physical properties
- (C) Degree of turbulence
- (D) Interfacial area
9. If mass diffusivity in a mixture is equal to the thermal diffusivity, then the Lewis number is
- (A) 0
- (B) 1
- (C) < 1
- (D) > 1
10. Which of the following solutions will follow Raoult's law most closely?
- (A) A solution of
benzene, toluene and o-xylene
- (B) 35% solution of
camphor in water
- (C) 35% solution of NH3 in
water
- (D) A solution of polar
organic compounds (not of homologue of a series)
11. For continuous drying of granular or crystalline material, the dryer used is the __________ dryer.
- (A) Tunnel
- (B) Tray
- (C) Rotary
- (D) None of these
12. Pick out the correct statement.
- (A) In case of
liquid-liquid extraction, no separation is possible, if the selectivity of the
solvent used is unity
- (B) With
increase in temperature, the selectivity of the solvent used in solvent
extraction decreases
- (C) The selectivity of
solvent used in solvent extraction is unity at the plait point
- (D) All (a), (b) and (c)
13. __________ column is preferred to be used, when a high liquid hold up is required in a reactor for gas-liquid reaction.
- (A) Packed
- (B) Bubble
- (C) Spray
- (D) Tray
14. As complete saturation of an adsorbent is approached, the differential heat of adsorption approaches
- (A) That of normal
condensation
- (B) Integral heat of
adsorption
- (C) Zero
- (D) None of these
15. During bottling of cold drinks (e.g. Pepsi), the main resistance to mass transfer for the absorption of carbon dioxide in water lies in the
- (A) Gas film
- (B) Liquid film
- (C) Liquid-gas interface
- (D) None of these
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