Practice Test: Question Set - 25
1. The film penetration model of mass transfer was enunciated by
- (A) Gilliland
- (B) Toor
and Marcello
- (C) Stefan
- (D) Fick
2. Equilibrium moisture of a solid is equal to the total moisture minus free moisture. Which of the following substances will have maxi-mum equilibrium moisture?
- (A) Anthracite coal
- (B) Rag paper
- (C) Bamboo
- (D) Inorganic solids
3. (NRe . NSc) is termed in mass transfer operation as the __________ number.
- (A) Stanton
- (B) Sherwood
- (C) Peclet
- (D) None of these
4. At a given equilibrium pressure, with increase in temperature, the concentration of adsorbed gas on solid adsorbent
- (A) Increases
- (B) Decreases
- (C) Remains unchanged
- (D) Increases
exponentially
5. With lapse of time, the overhead composition of light component in case of batch distillation with constant reflux
- (A) Increases
- (B) Decreases
- (C) Remain same
- (D) May increase or
decrease; depends on system
6. HETP is numerically equal to HTU, only when the operating line
- (A) Lies below the
equilibrium line
- (B) Lies above the
equilibrium line
- (C) And equilibrium lines
are parallel
- (D) Is far from the
equilibrium line
7. The operation involved when the soluble material is largely on the surface of an insoluble solid and is merely washed off by the solvent is called
- (A) Decoction
- (B) Percolation
- (C) Elutriation or
elution
- (D) None of these
8. __________ number indicates the ratio of the rates of the heat and mass transfer incase of a cooling tower.
- (A) Sherwood
- (B) Stanton
- (C) Lewis
- (D) Peclet
9. The recovery of penicillin from the acidified fermentation broth is done by
- (A) Distillation
- (B) Evaporation
- (C) Absorption
- (D) Liquid extraction
10. Drift in a cooling tower is
- (A) The water entrained
by the circulating air
- (B) Dependent
on the water lost by evaporation
- (C) Desirable
- (D) All (a), (b) &
(c)
11. In McCabe-Thiele method, at infinite reflux ratio
- (A) The overhead product
is minimum
- (B) Both the operating
lines coincide with diagonal
- (C) Both (a) and (b)
- (D) Neither (a) nor (b)
12. Gaseous diffusivity at atmospheric pressure is of the order of __________ cm2/second.
- (A) 1
- (B) 1 to 5
- (C) 5 to 10
- (D) > 10
13. Absorption factor, for a fixed degree of absorption from a fixed amount of gas should be
- (A) 1
- (B) > 1
- (C) < 1
- (D) ≤ 1
14. Pick out the wrong statement.
- (A) With decrease in feed
temperature, the number of plates required for binary distillation decreases
for a given ‘L/V’ ratio
- (B) The extraction per
unit of total height for a short packed column is more effective than for a
tall column, in case of liquid-liquid extraction
- (C) Natural draft cooling
towers are made of ferroconcrete and its cross-section is wider at the bottom
- (D) Vander wall
adsorption is also called chemisorption
15. Molarity is defined as the number of gm moles of solute per __________ of solvent.
- (A) Liter
- (B) kg
- (C) gm
- (D) c.c
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