Mass Transfer Quiz 1

A solid is being dried in the linear drying rate regime from moisture content Xo to XF. The drying rate is zero at X = 0 and the critical moisture content is the same as the initial moisture Xo. The drying time for M = (Ls/ARc) is (where, L = total mass of dry solid, A = total surface area for drying Rc = Constant maximum drying rate per unit area X = moisture content (in mass of water/mass of dry solids)) ?

___________ is concerned with the adsorption equilibria?

Absorption factor method is used to calculate the number of ideal stages, when_________?

______ extractor is used for the concentration of radioactive nuclear waste?

(NSh/NRe.NSc) is termed in mass transfer operation as the _____?

A packed tower compared to a plate tower for a particular mass transfer operation___________?

________ column is used in gas absorption process ?

________ extractor is used for the concentration of radioactive nuclear waste?

Air at a particular humidity is heated in a furnace. The new dew point_______?

A good solvent used for absorption should not have very high______?

______ temperature is the steady state temperature attained by a small amount of liquid evaporating into a large quantity of unsaturated gas-vapor mixture ?

Absorption accompanied with chemical reaction is exemplified by the absorption of_____?

______ is used as an ?entrainer? for the separation of acetic acid-water mixture by distillation?

According to Chilton-Colburn analogy for mass transfer, NSt.NSc 2/3 is equal to__________?

A liquid mixture contains 30% o-xylene, 60% p-xylene and 10%. m-xylene (all percentages in w/w). Which of the following statements would be true in respect of this mixture ?

Alcohol is dehydrated using _______ distillation?

________ number indicates the ratio of the rates of the heat and mass transfer incase of a cooling tower?

_____ extractor uses centrifugal force for separating the two phases?

__________ is the separation technique used for desalination of sea water ?

Alcohol is dehydrated using _________ distillation?

Acetic acid will be most economically separated from a dilute solution of acetic acid in water by______?

_______ column is the most suitable for achieving the best performance for mass transfer operations involving liquid with dispersed solids ?

Absorption factor, for a fixed degree of absorption from a fixed amount of gas should be__________?

________ columns are used for liquid dispersion in a continuous gas phase ?

A pure drug is administered as a sphere and as a cube. The amount of drug is the same in the two tablets. Assuming that the shape and size do not influence the mass transfer, the ratio of rate of dissolution in water at t = 0 for the cubic to spherical tablet is_____?

A binary mixture of benzene and cyclohexane is separated by_____?

A slurry is to be dried to produce flaky solid. Which dryer would you recommend ?

Absorption factor is defined as (where, S1 = slope of the operating line S2 = slope of the equilibrium curve) ______?

A 25 cm ? 25 cm ? 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 ? 1m ? 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 ______?

(NRe . NSc) is termed in mass transfer operation as the _______ number?

?ADDUCTS? and ?CLATHRATES? are used in case of_______?

A plait point is the point on the solubility curve, where the tie line reduces to a point. What is the number of plait point for a ternary system containing two pairs of partially miscible liquids ?

_______ column is preferred to be used, when a high liquid hold up is required in a reactor for gas-liquid reaction ?

A solid is being dried in the linear drying rate regime from moisture content Xo to XF. The drying rate is zero at X = 0 and the critical moisture content is the same as the initial moisture Xo. The drying time for M = (Ls/ARc) is (where, L = total mass of dry solid, A = total surface area for drying Rc = Constant maximum drying rate per unit area X = moisture content (in mass of water/mass of dry solids))______?

Absorption (liquid-gas system) with evolution of heat as compared to isothermal absorption results in__________?

?Absorption with chemical reaction? is involved in the removal of___________?

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 ?

Agitator is provided in a crystalliser for______?

A natural draft cooling tower is filled with wooden grids, which covers about __________ percent of the tower height?

________ diffusion is used for separating the isotopes of methane ?

A coalescer in a mixer-settler liquid-liquid extraction column________?

Adsorption is a unit operation which generally involves ________ systems?

According to Poiseuille?s law, the permeability for gas flow through a capillary is proportional to (where, ? = gas viscosity)_____?

________ developed the film theory ?

A minimum boiling azeotrope is exemplified by_____?

Absorption accompanied by heat evolution results in______?

______ is the temperature at which a gas-vapor mixture becomes saturated, when cooled at constant total pressure out of contact with a liquid ?

A solid material shows case hardening properties while drying. Which of the following should be controlled to control the drying process ?

According to the film theory of mass transfer, the mass transfer co-efficient is proportional to (where, D = molecular diffusivity) ?

A distillation column separates 10000 kg/hr of a benzene-toluene mixture as shown in the figure below: In the figure xF, xD and xW represent the weight fraction of benzene in the feed, distillate and residue respectively. The reflux ratio is________ ?