Q.1
An aqueous solution of methanol is to be distilled in a tray column. High pressure steam is available as a source of heat. For a given reflux ratio and overhead composition, two options are being explored; (i) a reboiler is used and (ii) no reboiler is used but steam is fed directly to the bottom of the column. As compared to option (i), in option (ii)
Q.2
In distillation where q is defined as the moles of liquid flow in the stripping section per mole of feed introduced, for saturated liquid feed
Q.3
Pick out the wrong statement.
Q.4
If G = insoluble gas in gas stream and L = non-volatile solvent in liquid stream, then the slope of the operating line for the absorber is
Q.5
Use of raschig rings in place of crushed stones as packing in packed beds (other things being same)
Q.6
Prandtl number for water at 20°C is about
Q.7
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?
Q.8
Surface renewal model of mass transfer was enunciated by
Q.9
At the boiling point of the liquid at the prevailing pressure, the saturated absolute humidity becomes
Q.10
Pick out the correct statement.
Q.11
__________ diffusion is used for separating the isotopes of methane.
Q.12
Blowdown in a cooling tower
Q.13
Boiling point diagram is
Q.14
Bollman extractor
Q.15
Entrainer used in azeotropic distillation should
Q.16
NSc/NPr is called the
Q.17
The humid volume may be increased by increasing the
Q.18
In case of cooling towers, the ratio of the rates of heat and mass transfer is indicated by the __________ number.
Q.19
The diffusivity (D) in a binary gas mixture is related to the temperature (T) as
Q.20
McCabe-Thiele method of binary distillation does not assume that the
Q.21
Which of the following parameters remains almost constant during adiabatic saturation of unsaturated air?
Q.22
An example of elutioh is
Q.23
Pick out the correct statement.
Q.24
The Schmidt number which is defined as, μ/ρ D, is the ratio of the
Q.25
Relative volatility does not change appreciably with the change in
Q.26
Leaching of sugar from sugar beets is done by
Q.27
Plate towers are preferred to packed towers, when large temperature changes are involved, because of the reason that the
Q.28
In an operating distillation column, the
Q.29
Dry bulb temperature of unsaturated air is more than its __________ temperature.
Q.30
In a packed bed absorption column, the channelling will be noted by the
Q.31
In a packed tower, the value of HETP equals HTUOG, when the equilibrium and the operating lines are (where, HETP = height equivalant to a theoretical plate HTUOG = overall gas phase height of a transfer unit)
Q.32
The film penetration model of mass transfer was enunciated by
Q.33
In extraction, as the temperature increases, the area of hetrogeneity (area covered by binodal curve)
Q.34
For the gas absorption, the height of a transfer unit, based on the gas phase is given by (G: superficial molar gas velocity, L: superficial molar liquid velocity, FG:mass transfer co-efficient, mols/m² , a: in-terfacial area per unit volume of tower)
Q.35
In distillation column design, the McCabe-Thiele procedure is inadequate and a Ponchan-Savarit procedure is needed, when
Q.36
Moisture contained by a substance in excess of the equilibrium moisture is called the __________ moisture.
Q.37
Moisture content of a substance when at equilibrium with a given partial pressure of the vapour is called the __________ moisture.
Q.38
Moisture in a substance exerting an equilibrium vapour pressure less than that of pure liquid at the same temperature is called the __________ moisture.
Q.39
Decoction refers to the use of solvent
Q.40
Selectivity of the solvent used in solvent extraction should be
Q.41
For the same process conditions, the reflux ratio of an unlagged distillation column
Q.42
The equipment frequently used for adiabatic humidification-cooling operation with recirculating liquid is
Q.43
Condensation of a vapour-gas mixture just begins, when (where, p = partial pressure of the vapour P = vapour pressure of the liquid )
Q.44
Penetration model (theory) for mass transfer was enunciated by
Q.45
Moisture in a solid exerting an equilibrium vapour pressure equal to that of the pure liquid at the same temperature is called the __________ moisture.
Q.46
Diameter of raschig rings used in packed tower in industry is normally around __________ inches.
Q.47
If the solubilities of different components (in a liquid-liquid extraction system) increase with rise in temperature, then the temperature above which they dissolve completely is known as the critical solution temperature (CST or consolute temperature). If solubilities increase with decrease in temperature, then CST is the temperature below which they dissolve completely. If a binary system has no critical solution temperature, it implies that
Q.48
The slope of the operating line for a single component co-current absorber when plotted in terms of mole ratio units is
Q.49
Can the efficiency of a plate in the distillation tower be greater than 100%?
Q.50
Air at a particular humidity is heated in a furnace. The new dew point
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