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.Management Sciences
Category: Mass Transfer
Packed column distillation is limited to the column _____________ metres?
A. Height < 6
B. Diameter < 0.6
C. Both A. & B.
D. Neither A. nor B.
Separation of a mixture of two gases by absorption in the liquid solvent depends upon the difference in their____________________?
A. Viscosity
B. Density
C. Solubility
D. Relative volatility
When an unsaturated air-water mixture is heated at constant pressure, then ____________________ ?
A. The partial pressure of water vapour increases
B. The specific humidity decreases
C. The relative humidity increases
D. The relative humidity decreases
When acetone is added in a two layer mixture of methyl isobutyl ketone and water at 30°C, the acetone distributes between the two layers and the composition of the layer follows two solubility curves. For this system ?
A. As the acetone concentration increases, the solubility curves approach each other
B. Both the phases become identical at a particular common point on both the solubility curves
called the plait point
C. The distribution curve which is a plot between x (acetone concentration in one phase) and y
(acetone concentration in other phase) is analogous to x-y curve used in distillation and
absorption terminates on the x = y diagonal at the concentration of the plait point
D. All A., B. and C.
Deaeration (removal of O2) of water is done by_________________?
A. Rectification
B. Absorption
C. Ion-exchange
D. Adsorption
Diffusion in concentrated solutions differs from that in dilute solutions, because of the change in the _______________ with the concentration of the solution?
A. Degree of ideality
B. Viscosity
C. Both A & B
D. Neither A nor B
For the air water system under ambient conditions, the adiabatic saturation temperature and the wet bulb temperature are nearly equal, because__________________?
A. Water has a high latent heat of evaporation
B. Lewis number is close to unity
C. They are always equal under all circumstances
D. Solubility of the components of air in water is very small
A distillation column with N plates is being operated under normal conditions. At some point of time, the operation is shifted to total reflux condition (i.e., no product and residue are being withdrawn and feed to the column is stopped). At the new steady state ?
A. Composition of vapors and that of liquid do not vary throughout the column
B. Reboiler load and condenser load are minimum
C. The top and bottom compositions are unchanged with and without total reflux
D. The top and bottom compositions correspond to the maximum enrichment available
Air initially at 101. 3 kPa and 40°C and with a relative humidity of 50%, is cooled at constant pressure to 30°C. The cooled air has a____________________?
A. Higher dew point
B. Higher absolute (specific) humidity
C. Higher relative humidity
D. Higher wet bulb temperature
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