Mass Transfer Quiz 2

Can a cooling tower cool water below the wet bulb temperature of inlet air ?

Coffee is prepared from coffee beans by leaching with______?

Ammonia present in the coke oven gas is removed by washing with_____?

At minimum reflux ratio for a given separation___________?

An ideal tower packing should not _________?

Capacity of a rotary dryer depends on its ___________?

Batch tray dryers suffers from the disadvantage of________?

Blowdown in a cooling tower______?

Azeotropism for ethyl alcohol-water system disappears by_______?

At equilibrium the concentration of water in vapour phase (C*) in kg/m3 of air space and the amount of water (m) adsorbed per kg of dry silica gel are related by, C* = 0.0667m. To maintain dry conditions in a room of air space 100m3 containing 2.2 kg of water vapour initially, 10 kg of dry silica gel is kept in the room. The fraction of initial water remaining in the air space after a long time (during which the temperature is maintained constant) is__________?

At 750?K and 1 atm, the approximate value of Schmidt number for air is__________?

At what value of reflux ratio, number of theoretical plates in a distillation column is minimum ?

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) ______?

At the boiling point of the liquid at the prevailing pressure, the saturated absolute humidity becomes________?

At a fixed pressure, the humidity depends upon the partial pressure of vapor in the mixture. Humidity of a vapour free gas is _________ percent.?

Below is given an equilibrium moisture curve of a substance. State which regions represent free moisture and unbound moisture respectively ?

Bound moisture is that liquid which exerts an equilibrium vapor pressure _________ that of the pure liquid at the given temperature ?

An Azeotropic mixture is a _________ mixture?

At a given equilibrium pressure, with increase in temperature, the concentration of adsorbed gas on solid adsorbent ___________?

Blowdown in a cooling tower___________?

At a fixed total pressure, humidity depends only on the _________?

Channelling is most severe_______?

Corresponding to Prandtl number in heat transfer, the dimensionless group in mass transfer is the ________ number?

As the reflux ratio in a distillation column is increased from the minimum, the________?

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___________?

Binary distillation involves the mass transfer by ________ at the gas-liquid interface?

Boiling point diagram is not affected by the ambient________?

Calculation of mass transfer co-efficient is mostly/normally done using _______ theory?

At ___________ reflux, theoretical number of plates in a distillation coloumn is calculated using Fenske-Underwood equation?

At constant pressure, with increase of temperature, the dew point will __________?

Calcium ammonium nitrate (a fertiliser) is dried in a __________ dryer?

As complete saturation of an adsorbent is approached, the differential heat of adsrop-tion approaches ______?

Channelling in a packed tower results from the_______?

Ammonia present in the coke oven gas is removed by washing with_____?

At the boiling point of the liquid at the prevailing pressure, the saturated absolute humidity becomes_______?

Back-trapping in a distillation column ?

As per Gilliland?s equation, the diffusivity is_____?

All moisture in a non-hygroscopic material is the _________ moisture?

Berl saddle made of carbon cannot be used for _____?

At the same gas flow rate, the pressure drop in a packed tower being irrigated with liquid ________ that in dry packed tower ?

An example of elution is________?

CO2 can be absorbed by______?

Bollman extractor_____?

Can the efficiency of a plate in the distillation tower be greater than 100% ?

Corresponding to Nusselt number in heat transfer, the dimensionless group in mass transfer is the _________ number?

Condensation of a vapour-gas mixture just begins, when (where, p = partial pressure of the vapour P = vapour pressure of the liquid) ?

Co-current absorbers are usually used when the gas to be dissolved in the liquid is _____?

At what percentage (by volume) of alcohol composition, it forms an azeotrope with water ?

As the reflux ratio decreases, the__________?

Can the efficiency of a plate in the distillation tower be greater than 100% ?