Q.1
Experimental determination of __________ is done by wetted wall column method.
Q.2
Coffee is prepared from coffee beans by leaching with
Q.3
The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are same for, NPr = NSc = __________
Q.4
The interfacial area per unit volume of dispersion, in a gas-liquid contactor, for fractional hold up of gas = 0.1 and gas bubble diameter = 0.5 mm is given by (in m²/m³)
Q.5
The ratio of Murphree plate efficiency to point efficiency is 1 in a __________ flow model.
Q.6
In case of liquids, the binary diffusivity is proportional to (where, T = temperature)
Q.7
Which of the following assumes constant molal vaporisation and overflow?
Q.8
The wetted wall tower is used to determine
Q.9
Flights in a rotary dryer are provided to
Q.10
Compound A is extracted from a solution of A + B into a pure solvent S. A Co-current unit is used for the liquid-liquid extraction. The inlet rate of the solution containing A is 200 moles of B/hr.m² and the solvent flow, rate is 400 moles of S/m². hr. The equilibrium data is represented by Y = 3X² , where Y is in moles of a A/moles of B and X is in moles A/moles of S. The maximum percentage extraction achieved in the unit is
Q.11
__________ column is preferred to be used, when a high liquid hold up is required in a reactor for gas-liquid reaction.
Q.12
The surface renewal frequency in Danckwerts model of mass transfer is given by (KL: mass transfer co-efficient)
Q.13
Unsaturated air (with dry bulb and wet bulb temperatures being 45°C and 25°C respectively) is passed through a water spray chamber maintained at 23°C. The air will be cooled and
Q.14
Flooding in a distillation column is detected by a sharp
Q.15
With increase in the liquid flow rate at a fixed gas velocity in a randomly packed counter current gas-liquid absorption column, the gas pressure drop
Q.16
Which of the following is directly concerned with psychrometry?
Q.17
In case of an unsaturated mixture of gas and vapor, the percentage saturation is __________ its relative saturation.
Q.18
Percentage saturation is __________ the relative saturation.
Q.19
In a packed absorption tower, if the equilibrium and operating lines are both straight lines, then the ratio, HETP/HTUOG __________ the absorption factor.
Q.20
Flooding in a vapor-liquid contacting equipment occurs in a tray, when the pressure drop through a tray is __________ the liquid head available in the downcomer.
Q.21
Unsaturated air (with dry and wet bulb temperatures being 35 and 25°C respectively) is passed through water spray chamber maintained at 35°C. The air will be
Q.22
Which of the following binary systems is an example of a maximum boiling azeotrope?
Q.23
Capacity of a rotary dryer depends on its
Q.24
When the temperature and humidity of air is low, we usually use __________ draft cooling tower.
Q.25
For the flow of gases through a capillary, with increase in temperature, the permeability __________ as per Knudsen law.
Q.26
Extraction of pencillin employs a __________ extraction coloumn.
Q.27
Pick out the correct statement.
Q.28
Experiments were conducted to determine the flux of a species A in a stagnant medium across a gas-liquid interface. The overall mass transfer co-efficient based on the liquid side for dilute systems for the above was estimated to be 4 x 10⁻³ kg mole/m².s. The equilibrium data for the system is given as y = 2x. The flux across the interface (in kg mole/m² .s) for bulk concentrations of A in gas phase and liquid phase as y = 0.4 and x = 0.01 respectively is
Q.29
Which is not concerned directly with mass transfer?
Q.30
Operating velocity in a packed tower is usually __________ the flooding velocity.
Q.31
Humid volume, at a given temperature is a/an __________ function of humidity.
Q.32
In a liquid-liquid extraction, 10 kg of a solution containing 2 kg of solute C and 8 kg of solvent A is brought into contact with 10 kg of solvent B. Solvent A and B are completely immiscible in each other whereas solute C is soluble in both the solvents. The extraction process attains equilibrium. The equilibrium relationship between the two phases is Y* = 0.9X, where Y* is the kg of C/kg of B and X is kg of C/kg of A. Choose the correct answer.
Q.33
Removal of __________ exemplifies an adsorption unit operation.
Q.34
Pick out the wrong statement pertaining to the analogy between equations of heat and mass transfer operations.
Q.35
The relative volatility of a binary mixture at constant temperature __________ the total pressure.
Q.36
For the case of flow of air past a wet bulb thermometer (air water vapour system), the approximate value of H₂/ky.Cz is around
Q.37
Small dia distillation column can be a
Q.38
__________ developed the film theory.
Q.39
On addition of solute in the solvent, the __________ of the solution decreases.
Q.40
Binary distillation involves the mass transfer by __________ at the gas-liquid interface.
Q.41
A natural draft cooling tower is filled with wooden grids, which covers about __________ percent of the tower height.
Q.42
HETP is numerically equal to HTU, only when the operating line
Q.43
The drying time between fixed moisture content within diffusion controlled 'falling rate period' is proportional to (assuming that drying occurs from all surfaces of the solid) (where, T = thickness of the solid )
Q.44
The drying time between fixed moisture contents within the 'constant rate period' is proportional to (assuming that drying occurs from all surfaces of the solid) (where, T = thickness of the solid )
Q.45
Wet bulb and dry bulb temperatures becomes identical at __________ percent saturation curve.
Q.46
At the same gas flow rate, the pressure drop in a packed tower being irrigated with liquid __________ that in dry packed tower.
Q.47
The temperature of water cooled in cooling tower is always __________ temperature of entering air.
Q.48
When adsorption hysteresis is observed, the desorption equilibrium pressure is __________ that obtained by adsorption.
Q.49
If the specific heats of a gas and a vapor are 0.2KJ/Kg.°K and 1.5 KJ/Kg.°K respectively, and the humidity is 0.01; the humid heat in KJ/°Kg. is
Q.50
In case of constant underflow extraction operation, the __________ at all solute concentration.
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