Which of the following processes is not an example of adsorption applied to gaseous separations?
A. Recovery of valuable solvent vapors from dilute mixture with air and other gases
B. Dehumidification of air and gas
C. Removal of objectionable odour and impurities from industrial gases
D. Decolouration of yellow glycerene
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If f is defined as above, then which of the following applies to a feed at dew point?
A. F = 1
B. F < 1
C. F > 1
D. 0 < f < 1
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Design calculation for multiple component distillation is done by
A. Ponchon-Savarit method
B. Mccabe-Thiele method
C. Enthalpy concentration method
D. Tray to tray calculations
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Cox chart, which is useful in the design of distillation column particularly for petroleum hydrocarbons, is a plot of (where, P = vapor pressure, T = temperature)
A. Log P vs . T
B. Log P vs. log T
C. T vs . P
D. P vs . log T
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In batch distillation with constant reflux, overhead product composition __________ with time.
A. Increases
B. Decreases
C. Does not vary
D. May increase on decrease, depends on the system
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Back-trapping in a distillation column
A. Increases tray efficiency
B. Decreases tray efficiency
C. Reduces pressure drop
D. Is desirable, as it provides improved vapour-liquid contact
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Agitator is provided in a crystalliser for
A. Avoiding deposition on cooler surfaces
B. Formation of nuclei
C. Crystal growth
D. All of the above
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Chemisorption (chemical adsorption) is
A. Same as "Van der Waals" adsorption
B. Characterised by adsorption of heat
C. An irreversible phenomenon
D. A reversible phenomenon
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Desirable value of absorption factor in an absorber is
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Bound moisture is that liquid which exerts an equilibrium vapor pressure __________ that of the pure liquid at the given temperature.
A. Less than
B. More than
C. Equal to
D. Either A or B; depends on the solid
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A coalescer in a mixer-settler liquid-liquid extraction coloumn
A. Comprises of thin bed of substances of extended surface having high porosity
B. Helps in increasing the bubble size entering the settler
C. Helps in increasing the settling rate of the bubbles
D. All of the above
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Tower diameter may be decreased by
A. Using higher reflux ratio
B. Use of increased tray spacing
C. Increasing the liquid flow rate
D. Increasing the vapour flow rate
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In a moderately sized packed absorption tower, channeling (which is most severe with stacked packings) can be minimised by taking the ratio of tower diameter to packing diameter
A. > 4 :1
B. < 8 : 1
C. > 8:1
D. < 6:1
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Flash distillation is suitable for the separation of components
A. Having very close boiling points
B. Which form maximum boiling azeotrope
C. Having very wide boiling points
D. Which form minimum boiling azeotrope
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Make up water is required in a cooling tower to replace the water lost by
A. Evaporation
B. Drift
C. Blowdown and leakage
D. All of the above
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In an absorber, HETP does not vary with the
A. Flow rate of liquid
B. Flow rate of gas
C. Type and size of packing
D. None of these
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Use of natural draft cooling tower is practised, when the air has low
A. Humidity
B. Temperature
C. Both A & B
D. Neither A nor B
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Raoult's law applies to the
A. All liquid solutions
B. Non-ideal solution only
C. Non-volatile solute
D. Solvents
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The difference of wet bulb temperature and adiabatic saturation temperature of unsaturated mixture of any system is
A. +ve
B. -ve
C. Zero
D. None of these
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Which of the following can be calculated theoretically using steam table and Dalton's law of partial pressure; if the relative humidity and dry bulb temperature of moist air is known?
A. Dew point
B. Humidity ratio
C. Wet bulb temperature
D. None of these
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