Q.1
Acetic acid will be most economically separated from a dilute solution of acetic acid in water by
Q.2
Minimum possible diameter of a packed coloumn is decided mainly by the
Q.3
In triangular co-ordinates, the ternery composition point falls __________ of the triangle.
Q.4
The dew point of a saturated gas phase equals the __________ temperature.
Q.5
The critical moisture content in case of drying indicates the __________ rate period.
Q.6
Rayleigh's equation applies to __________ distillation.
Q.7
For a distillation column operating at minimum reflux, the
Q.8
The wet and 'dry bulb temperature for a vapour-gas mixture are 25°C and 30°C respectively. If the mixture is heated to 45°C at constant pressure, the wet bulb temperature will be __________ °C.
Q.9
The Kundsen diffusivity is proportional to (where, T = absolute temperature)
Q.10
Langmuir equation is associated with
Q.11
Large scale drying of wheat is done in a __________ dryer.
Q.12
In case of steam distillation, the steam leaving the liquid is not completely saturated with distillate vapour, because
Q.13
__________ is concerned with the adsorption equilibria.
Q.14
The change in enthalpy per unit weight of adsorbed gas when adsorbed on gas free or "outgassed" adsorbent to from a definite concentration of adsorbate is called its
Q.15
Total reflux in a distillation operation requires minimum
Q.16
When the solvent dissolves very little of solute, then
Q.17
For __________ drying, the effects of velocity, temperature and humidity of the gas and the thickness of the solid are the same.
Q.18
Ion exchange process is similar to
Q.19
Pick out the wrong statement pertaining to the rotary dryer.
Q.20
To remove all the moisture from a wet solid it requires exposure to __________ air.
Q.21
Large scale drying of sugar is done in a __________ dryer.
Q.22
Weeping in a distillation column
Q.23
Steady state equimolal counter diffusion is encountered in
Q.24
For turbulent mass transfer in pipes, the Sherwood number depends on the Reynolds number as
Q.25
Make up water is supplied during cooling tower operation to compensate for water losses due to
Q.26
The Reynolds number of the liquid was increased 100 fold for a laminar falling film used for gas-liquid contacting. Assuming penetrating theory is applicable, the fold increase in the mass transfer co-efficient (Kc) for the same sytem is
Q.27
In distillation, overhead product contains
Q.28
When the __________ the relative humidity of air decreases, despite an increase in the absolute humidity.
Q.29
Molecular diffusivity of a liquid
Q.30
Mass transfer co-efficient (K) and diffusivity (D) are related according to film theory as
Q.31
During drying operation, it is easier to remove the __________ moisture.
Q.32
At constant pressure, with increase of temperature, the dew point will
Q.33
Steady state equimolal counter diffusion occurs in case of
Q.34
In liquid-liquid extraction, the number of phases at plait point is
Q.35
An alkaline solution is used to reduce the concentration of carbon dioxide in a stream from 10% to 0.1% by absorption with irreversible chemical reaction. The overall number of transfer units based on gas phase is
Q.36
Flash distillation is suitable for separating the constituents of a binary system, which
Q.37
Pick out the wrong statement.
Q.38
When the mixture to be distilled has a very high boiling point and the product material is heat sensitive, the separation technique to be used is __________ distillation.
Q.39
The temperature to which a vapour gas mixture must be cooled (at varying humidity) to become saturated is called the __________ temperature.
Q.40
Steady state temperature reached by a small amount of liquid evaporating into a large amount of unsaturated vapour-gas mixture is called the __________ temperature.
Q.41
Sand is dried in foundaries in a___drier.
Q.42
Which of the following adsorbant is used in the refinning of sugar?
Q.43
Absorption accompanied with chemical reaction is exemplified by the absorption of
Q.44
In gas-liquid contact operation, the number of ideal stages, N = (xa - xb)/(xb - x*b) . This is true when the stripping factor 'S' is
Q.45
The term "approach" in a cooling tower refers to the difference in the temperature of the
Q.46
Hypersorption refers to a __________ process.
Q.47
A 25 cm x 25 cm x 1 cm flat sheet weighing 1.2 kg initially was dried from both sides under constant drying rate conditions. It took 1500 seconds for the weight of the sheet to reduce to 1.05 kg. Another 1m x 1m x 1cm flat sheet of the same material is to be dried from one side only.Under the same constant drying rate conditions, the time required for drying (in seconds) from its initial weight of 19.2 kg to 17.6 kg is
Q.48
At 750°K and 1 atm, the approximate value of Schmidt number for air is
Q.49
The reason for preferring packed towers over plate towers in distillation practice is that the packed tower operation gives
Q.50
Which of the following gas-liquid contacting devices incurs the least pressure drop for a particular duty?
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