mtn4 Flashcards
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
C
Which of the following is the correct ternary diagram for liquid
liquid extraction system comprising of two pairs partly soluble
(e.g., chlorobenzene-water-methyl ethyl ketone system)?
A
Steam distillation is used for separation of high boiling
A. substances from non-volatile impurities.
B. volatile impurity from still higher boiling substances.
C. both (a) and (b).
D. neither (a) nor (b).
C
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.
C
The feed to fractionating column is changed from saturated
vapour to saturated liquid. If the separation and reflux ratio
remains unchanged, the number of ideal stages will
A. increase
B. decrease
C. remains same
D. depend on saturated boiling point; may increase or
decrease
A
Rose oil is extracted from rose leaves using _______ distillation.
A. high pressure
B. low pressure
C. extractive
D. steam
D
Rose = steam
Hypersorption refers to a __________ process.
A. fixed bed absorption
B. moving bed absorption
C. fixed bed adsorption
D. moving bed adsorption
D
Extraction of coffee from its seed is done by
A. liquid-liquid extraction.
B. leaching.
C. extractive distillation.
D. steam distillation.
B
In azeotropic mixture, the equilibrium vapour composition is
A. more than liquid composition.
B. less than liquid composition.
C. same as liquid composition.
D. independent of pressure.
C
(Eq = same)
With lapse of time, the overhead composition of light component
in case of batch distillation with constant reflux
A. increases
B. decreases
C. remains same
D. may increase or decrease ; depends on system.
B
lapse = decrease
According to the film theory of mass transfer, the mass transfer
co-efficient is proportional to (where, D = molecular diffusivity)
A. D
B. D2
C. D0.5
D. 1/D
A
Dry bulb temperature of the gas is _____ the wet bulb temp.
A. less than
B. more than
C. equal to
D. none of these
B
Decoction refers to the use of solvent
A. at ambient temperature
B. at its boiling point
C. in its vapor form
D. none of these
B
Flooding in a column results due to
A. high pressure drop
B. low pressure drop
C. low velocity of the liquid
D. high temperature
A
Flash distillation is suitable for separating the constituents of a
binary system, which
A. form minimum boiling azeotrope.
B. have very wide boiling points.
C. have very close boiling points.
D. form constant boiling azeotrope.
B
Lewis number, which is important in problems involving
simultaneous heat and mass transfer, is the ratio of
A. mass diffusivity to momentum diffusivity.
B. thermal diffusivity to mass diffusivity.
C. momentum diffusivity to thermal diffusivity.
D. none of these.
B
The ratio of Murphree plate efficiency to point efficiency is 1 in a
__________ flow model.
A. Plug
B. perfectly mixed
C. both (a) & (b)
D. neither (a) nor (b)
B
The rough value of diffusion co-efficient of water vapor into air
at 25°C may be about __________ cm2/sec.
A. 0.25
B. 2.5
C. 1.25
D. 0.0025
A
Which of the following gas-liquid contacting devices incurs the
least pressure drop for a particular duty ?
A. Grid tray tower
B. Perforated tray tower
C. Wetted wall tower
D. Bubble cap tower
C
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?
A. The mixture exhibits an azeotrope at 101.3 kPa.
B. The composition of the mixture, in percent by volume
is: o-xylene 30, p-xylene 60. and m-xylene 10.
C. The composition of the mixture in mole percent is: o
xylene 30, p-xylene 60 and m-xyoene 10.
D. The mixture contain optical isomers.
A
Unsaturated air (with dry bulb temperature and dew point being
35°C and 18°C respectively) is passed through a water spray
chamber maintained at 15°C. The air will be cooled
A. and humidified.
B. and dehumidified with increase in wet bulb
temperature.
C. at the same relative humidity.
D. and dehumidified with decrease in wet bulb
temperature.
D
Unit operation involved in the prilling of urea is
A. evaporation
B. drying
C. crystallization
D. both (b) and (c)
D
Pick out the wrong statement pertaining to leaching.
A. Fine solids can not be leached in a Pachuka tank.
B. Door classifier can be used for leaching of coarse
solids.
C. Vegetable seeds can be leached in either of Bollman
extractor, Rotocel or Kennedy extractor.
D. Very high temperature is not needed for the leaching of
sugar beet.
A
Molecular seives are porous
A. alumina.
B. silica.
C. synthetic zeolites crystals/metal alumino-silicates.
D. none of these.
C