(2) Mass Transfer Flashcards by Ella Angelan

Mass transfer rate between two fluid phases does not necessarily depend on the __________ of the two phases.

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In a solution containing 0.30 Kg mole of solute and 600 kg of solvent, the molality is

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Fenske equation determines the

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The term “cooling range” in a cooling tower refers to the difference in the temperature of

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Which of the following is the most suitable for extraction in a system having very low density difference?

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Total reflux in a distillation operation requires minimum

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The amount of steam required per unit quantity of distillate in case of steam distillation will be reduced by

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The difference of wet bulb temperature and adiabatic saturation temperature of unsaturated mixture of any system is

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Fenske’s equation for determining the minimum number of theoretical stages in distillation column holds good, when the

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When the temperature and humidity of air is low, we usually use __________ draft cooling tower.

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Pick out the correct statement.

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__________ columns are used for liquid dispersion in a continuous gas phase.

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Overall efficiency of the distillation column is

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On addition of solute in the solvent, the __________ of the solution decreases.

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Which is the controlling factor for a drum drier?

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Drying operation under vacuum is carried out to

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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

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Separation of two or more components of a liquid solution can not be achieved by

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Stefan’s law describes the mass transfer by

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At minimum reflux ratio for a given separation

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Relative humidity is the ratio of the

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In batch distillation with constant reflux, overhead product composition __________ with time.

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Psychrometry deals with the properties of gas-vapor mixture. Humidity can be determined by the measurement of the __________ of a fibre.

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Heat in BTU necessary to increase the temperature of 1 lb of gas and its accompanying vapour by 1°F is called the

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To increase the absorption factor, (where, G = gas flow rate, S = solvent flow rate)

The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are same for, NPr = NSc = __________

Dew point of a gas-vapour mixture

In a packed absorption tower, if the equilibrium and operating lines are both straight lines, then the ratio, HETP/HTUOG __________ the absorption factor.

Which of the following plays an important role in problems of simultaneous heat and mass transfer?

In case of an absorber, the operating

As the reflux ratio in a distillation coloumn is increased from the minimum, the

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

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 ternery system containing twopairs of partially miscible liquids?

Which of the following remains constant during sensible cooling process?

Physical absorption is

Make up water is required in a cooling tower to replace the water lost by

Which of the following quantities need not be fixed before starting the design of a co-current absorber?

Mass transfer co-efficient of liquid is

Absorption accompanied with chemical reaction is exemplified by the absorption of

Which of the following unit operations makes use of Thiele-Geddes equation?

Which of the following liquid-vapor contacting devices provides maximum contact surface area for a particular duty?

The equipment frequently used for adiabatic humidification-cooling operation with recirculating liquid is

Chemisorption (chemical adsorption) is

The rate of solid-liquid extraction is limited by the

Raoult's law applies to the

In distillation columns, the number of bubble caps per tray primarily depends upon the

In distillation, overhead product contains

With increase in pressure, the relative volatility for a binary system

Low viscosity absorbent is preferred for reasons of

Mass transfer co-efficient (K) and diffusivity (D) are related according to film theory as

The McCabe Δ L law states that the

Bollman extractor

The relation, Sc = Pr = 1, is valid, when the mechanism of __________ ansfer is same.

A coalescer in a mixer-settler liquid-liquid extraction coloumn

For the same feed, feed quality and separation (in a distillation column), with the increase of total pressure, the number of ideal plates will

Pick out the correct statement.

When the liquid phase and vapour phase of a binary system obeys Raoult's and Dalton's law respectively, the relative volatility is the ratio of

The operation involved when the soluble material is largely on the surface of an insoluble solid and is merely washed off by the solvent is called

In the constant rate period of the rate of drying curve for batch drying,

It takes 6 hours to dry a wet solid from 50% moisture content to the critical moisture content of 15%. How much longer it will take to dry the solid to 10% moisture content, under the same drying conditions? (The equilibrium moisture content of the solid is 5%).

Agitator is provided in a crystalliser for

__________ diffusion is used for separating the isotopes of methane.

Ordinary diffusion process is also called __________ diffusion.

Pick out the wrong statement.

Pick out the wrong statement pertaining to the rotary dryer.

The reason for preferring packed towers over plate towers in distillation practice is that the packed tower operation gives

If the path of liquid across the plate is very long as in case of large diameter tower, Murphree efficiency can be __________ percent.

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

Raoult's law is applicable to the

Weeping in a distillation column

In case of binary distillation, increasing the reflux ratio above optimum does not result in the increase of

Wetted wall tower experiment determines the

In McCabe-Thiele method, at infinite reflux ratio

With decrease in the throughput (compared with the design capacity) for a bubble cap distillation column, its efficiency

Plate towers are preferred to packed towers, when large temperature changes are involved, because of the reason that the

The equilibrium liquid composition compared to the vapor composition in case of azeotropic mixture is

Out of the following gas-liquid contacting devices, for a given set of operating conditions, gas pressure drop is the least in __________ tower.

Pick out the system with minimum boiling azeotrope at 1 atm.

Free flowing granular materials can be best dried in a __________ drier.

In case of an ideal solution, the total vapor pressure varies __________ with the composition expressed as mole fraction,

Corresponding to Nusselt number in heat transfer, the dimensionless group in mass transfer is the __________ number.

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

Liquid diffusivity is of the order of __________ cm2 /second.

The solvent used in liquid extraction should not have high latent heat of vaporisation, because

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

Molarity is defined as the number of gm moles of solute per __________ of solvent.

The value of Lewis number (Le = Sc/Pr) for air-water vapour system is around

Which of the following T-H diagram is valid for dehumidification operation?

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)

The partial pressure distribution of an ideal gas diffusing through another stagnant ideal gas at steady state follows a/an __________ law.

Which of the following binary systems is an example of a maximum boiling azeotrope?

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

The binary diffusivity in gases and liquids vary respectively as

Pick out the correct statement.

Very tall packed towers are divided into series of beds to

Moisture contained by a substance in excess of the equilibrium moisture is called the __________ moisture.

With increase in temperature, the solubility of gases in liquids, at fixed pressure

In most of the vacuum crystalliser, vacuum is generally produced by means of a

On moving the feed line (q-line) from saturated liquid feed (vertical position) to saturated vapor feed (horizontal feed), if the slope of both the operating lines are to be increased, then it will result in

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

Deairation (removal of O2) of water is done by

Make up water is supplied during cooling tower operation to compensate for water losses due to

Pick out the wrong statement.

A minimum boiling azeotrope is exemplified by

Which of the following solutions will follow Raoult's law most closely?

Use of raschig rings in place of crushed stones as packing in packed beds (other things being same)

Critical humidity of a solid salt means the humidity

The assumption made in Elis method in distillation is that enthalpy concentration lines of vapor and liquid are

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

Absorption with chemical reaction' is involved in the removal of

The-relative volatility for separation of a non-ideal binary mixture by distillation should be

Pick out the wrong statement:

In paper industry, paper is dried in a __________ dryer.

Pick out the wrong statement.

Only small amount of evaporation of water produces large cooling effects because of its

The most common packing used in industrial operations is __________ rings.

When the feed to a distillation column is a saturated liquid, slope of the feed line is

Leaching of sugar from sugar beets is done by

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

Flights in a rotary dryer are provided to

If f = moles of vapour present per mole of feed, then the slope of feed line is (Mcabe-Thiele method)

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

The rate of mass transfer is not dependent upon the

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

Dry bulb temperature of unsaturated air is more than its __________ temperature.

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

The reciprocal of stripping factor is termed as

Ponchan-Savarit method analyses the fractional equipment based on

The binary diffusivity in gases at atmospheric conditions is about

Percentage saturation is __________ the relative saturation.

In case of a desorber (stripper), the

What is the reflux ratio at total reflux?

Under conditions of flooding in packed tower, the gas pressure drop

For achieving rapid drying rate in a spray dryer, the diameter of the particles in the feed should be in the range of __________ microns (1 mm = 1000 microns).

For absorbing a sparingly soluble gas in a liquid

Channelling in a packed tower results from the

The change in enthalpy per unit weight of adsorbed gas when adsorbed on gas free or "outgassed" adsorbent to from a definite concentration of adsorbate is called its

The minimum number of theoretical plates is required for achieving a given separation in distillation column with

A good solvent used for absorption should not have very high

In a counter-current liquid extractor

Which of the following is an undesirable property for an absorbing solvent ?

The wetted wall tower is used to determine

Weight of 1 m3 of humid air as compared to 1 m3 of dry air, under the same conditions, is

Positive deviation from Raoult's law means a mixture whose total pressure is

With increase in gas rate, the number of transfer units, NtoG, for a fixed degree of absorption by a fixed amount of solvent

Schmidt number is given by

The caking of crystals can be prevented by

Prandtl number for water at 20°C is about

Boiling point diagram is

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,

Steam distillation is used to

Freundlich equation applies to the adsorption of solute from

For ethanol-water system, the lowering of distillate quality from 95% to 92% will cause __________ plate requirement.

The apex of an equilateral-triangular coordinate (in ternary liquid system) represents a/an

The diffusivity (D) in a binary gas mixture is related to the pressure (P) as

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

Which of the following psychrometric processes is followed by water vapour laden unsaturated air, when it is passed through solid or liquid adsorbent?

In gas-liquid contact operation, the number of ideal stages, https://www.indiabix.com/_files/images/chemical-engineering/mass-transfer/331-646-1.png . This is true when the stripping factor 'S' is (see picture)

The cooling effect in a cooling tower can not be increased by

The value of NA/(NA + NB) for steady state molecular diffusion of gas 'A' through non-diffusing gas 'B' is

The humid volume may be increased by increasing the

Pick out the wrong statement

When the mixture to be distilled has a very high boiling point and the product material is heat sensitive, the separation technique to be used is __________ distillation.

Large scale drying of wheat is done in a __________ dryer.

Azeotropic distillation is employed to separate

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)

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

Use of natural draft cooling tower is practised, when the air has low

Pressure drop through plate tower as compared to that through packed tower, for the same duty will be

Dimension of mass diffusivity is the same as that of

Dorr thickener is an equipment used for

Steam distillation is used to separate

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

Which of the following is an undesirable property in a tower packing?

Water entrained by circulating air in cooling towers is termed as

A 25 cm x 25 cm x 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 x 1m x 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

With increase in temperature, the rate of leaching increases, because the

Humidity chart is useful for the solution of problems concerning condensation, vaporisation and air conditioning. At a given dry bulb temperature, value of humidity obtained from the humidity chart directly, is in terms of __________ humidity. molal

The Kundsen diffusivity is proportional to (where, T = absolute temperature)

In case of constant underflow extraction operation, the __________ at all solute concentration.

In an absorption coloumn, the flooding velocity for random packing is __________ that for stacked/regular packing.

The relation among various mass transfer co-efficients (M.T.C) for ideal gases is given by (where, Kc & Km are M.T.C. for equimolar counter diffusion with concentration & mole fraction respectively as the driving force. and, Kp = M.T.C. for diffusion of a gas through a stagnant inert gas with pressure as driving force.)

With increase in temperature, the leaching rate increases because of the

Leaching of uranium ore and gold ore is done in

Blowdown in a cooling tower

During constant rate period, the rate of drying decreases with the

Antibiotics are best handled in a

The fixed cost of a distillation column at minimum reflux ratio is

__________ extractor uses centrifugal force for separating the two phases.

In a binary distillation column, if the feed contains 40 mole % vapour, the q line will have a slope of

Pick out the wrong statement.

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

Design calculation for multiple component distillation is done by

To get high tray efficiency

The mass transfer co-efficient for a solid sphere of radius 'a' dissolving in a large volume of quiescent liquid, in which D is the diffusivity of solute, is

Pick out the wrong statement. Generally for physical adsorption, a gas of

In most of the mechanically agitated liquid-liquid extractors, baffles or horizontal compartmental plates are provided, which helps in

In a vapor-liquid contacting equipment, the overall gas phase mass transfer co-efficient (M.T.C), KG is related to individual co-efficients (KG and KL) as

Solvent extraction is the terminology applied to the liquid-liquid extraction, which is preferred for the separation of the components of liquids, when

Inside the distillation column, the

Diffusivity in concentrated solutions differs from that in dilute solutions, because of the changes in

Occurrence of 'case hardening' during drying of a high moisture solid cake __________ the drying rate.

Which of the following is not a continuous drier?

Humidification involves mass transfer between a pure liquid phase and a fixed gas, which is

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

Rate of leaching increases with increasing

An azeotropic mixture is a __________ mixture.

Pick out the wrong statement.

Molecular seives are regenerated by heating to __________ °C.

In continuous distillation, the internal reflux ratio (Ri) and the external reflux ratio (Re) are related as

In a counter-current extractor, as the axial mixing increases, the extraction efficiency

Heat sensitive materials like certain pharmaceuticals and food stuffs can be dried in a/an __________ dryer.

In extractive distillation, solvent is

Radioactive nuclear waste is treated in

Large scale drying of sugar is done in a __________ dryer.

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

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)

__________ equation applies to diffusivities in liquids.

A packed tower compared to a plate tower for a particular mass transfer operation

Which of the following is the most commonly used leaching solvent in vegetable oil industry?

In an absorber, HETP does not vary with the

Large quantity of silica gel is normally dried in a __________ dryer.

For the same system, if the same liquid used in an absorber is decreased, the tower height will

Hydrogenation of oil is carried out in a/an __________ in Vanaspati manufacturing plant.

Sides of equilateral-triangular co-ordinates (on which ternary liquid system is plotted) represent

In distillation column design, the McCabe-Thiele procedure is inadequate and a Ponchan-Savarit procedure is needed, when

In an interphase mass transfer process, the lesser the solubility of a given solute in a liquid, the higher are the chances that the transfer process will be

As the reflux ratio decreases, the

Which of the following equipments is not used for gas dispersion?

One mole feed of a binary mixture of a given composition is flash vaporised at a fixed P and T. If Raoult's law is obeyed, then changing the feed composition would effect

The equation, https://www.indiabix.com/_files/images/chemical-engineering/mass-transfer/315-483-1.png is for (see attached picture)

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

The equation, https://www.indiabix.com/_files/images/chemical-engineering/mass-transfer/314-467-1.png is for (see attached ppicture)

Which of these columns incurs the lowest pressure drop?

In the desorption of highly soluble gas from the liquid, the main resistance will be in the __________ phase.

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

Which of the following remains constant during evaporative cooling process with recirculated water supply?

For stripping of a gas in a counter current stripper, the operating line

Which of the following same diameter columns gives lowest pressure drop per unit height?

Diffusion in concentrated solutins differs from that in dilute solutions, because of the change in the __________ with the concentration of the solution.

Stage efficiency in a leaching process depends on the

Operating velocity in a packed tower is usually __________ the flooding velocity.

The Knudsen diffusivity is dependent on the

Minimum possible diameter of a packed coloumn is decided mainly by the

Solvent used in extractive distillation

Capacity of a rotary dryer depends on its

The cooling effect in a cooling tower can be speeded up by

The following plot gives the saturated humidity (He) versus temperature (T).Line joining (H1, T1) and (H2, T2) is the constant enthalpy line. Choose the correct one from among the alternatives A, B, C and D. The following plot gives the saturated humidity (He) versus temperature (T).Line joining (H1, T1) and (H2, T2) is the constant enthalpy line. Choose the correct one from among the alternatives A, B, C and D. https://www.indiabix.com/_files/images/chemical-engineering/mass-transfer/335-677-1.png

When both the fluids flow concurrently in an absorber, the slope of the operating line is

The percentage humidity is less than the relative humidity only at __________ percent humidity.

Back-trapping in a distillation column

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.

Milk is dried usually in a __________ dryer.

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

Which of the following adsorbent is used to decolourise yellow glycerine?

Which of the following liquid temperature (T) Vs. vapor-gas mixture enthalpy (H) diagram is valid for humidification operation?

In a distillation column, with increase in the reflux ratio, the heat removed in the cooler

Pick out the wrong statement.

Which of the following is not a unit of mass transfer co-efficient?

The falling rate period in the drying of a solid is characterised by

In which of the following unit operations, the selectivity is an important parameter?

Which of the following is an undesirable characteristic for the solvent used in gas absorption?

Which of the following equipments is not used for liquid dispersion?

Diameter of raschig rings used in packed tower in industry is normally around __________ inches.

The diffusion co-efficient in m2 /s. of acetic acid in benzene (liquid in liquid) is

Pick out the wrong statement.

In case of non-ideal gases and liquids, the molal diffusivity

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

__________ number indicates the ratio of the rates of the heat and mass transfer incase of a cooling tower.

The expression, y(1 - x)/x(1 - y) is for

In physical terms, Schmidt number means

In case of liquids, the binary diffusivity is proportional to (where, T = temperature)

The diffusivity, DAB (for component A diffusing in B) is equal to the diffusivity DBA (for component B diffusing in A) for a binary mixture of

Mass transfer co-efficient is directly proportional to DAB0.5, according to __________ theory.

Sand is dried in foundaries in a___drier.

Which of the following employs an accessory known as 'drift eliminator'?

Pick out the correct statement.

Humid volume is the total volume in m3 of 1 kg of

Diameter to height ratio for a rashig ring is

The equipment used in the extraction of highly corrosive radio active liquids is

Advantage of continuous drying over batch drying is that the

With increase in temperature, the rate of extraction in leaching (solid-liquid extraction system)

In a packed bed absorption column, the channelling will be noted by the

Gaseous diffusivity at atmospheric pressure is of the order of __________ cm2/second.

In liquid-liquid extraction, the number of phases at plait point is

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.

The surface renewal frequency in Danckwerts' model of mass transfer is given by (KL: mass transfer co-efficient)

If Rm is the minimum reflux ratio, the optimum reflux ratio may be around __________ Rm.

During dehumidification of unsaturated air wet bulb temperature & partial pressure of vapor are not constant. However, during evaporative cooling process with recirculated water supply, the __________ remains constant.

In case of absorption, both the operating and equilibrium lines will be straight for

Mass transfer co-efficient varies as DAB0.5, according to the __________ theory.

For an absorber, both equilibrium and operating line will be straight for

A distillation column separates 10000 kg/hr of a benzene-toluene mixture as shown in the figure below: https://www.indiabix.com/_files/images/chemical-engineering/mass-transfer/335-680-1.png In the figure xF, xD and xW represent the weight fraction of benzene in the feed, distillate and residue respectively. The reflux ratio is

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

Humid volume, at a given temperature is a/an __________ function of humidity.

The Schmidt number which is defined as, μ/ρ D, is the ratio of the

If f is defined as above, then which of the following applies to a feed at dew point ?

Perforated plate towers are unique for solvent extraction because, they provide

In case of absorption & stripping, the interface of the liquid & gas phases are present in equilibrium, when the diffusional resistance of __________ is zero.

Pick out the wrong statement pertaining to the analogy between equations of heat and mass transfer operations.

The slope of the operating line for a single component co-current absorber when plotted in terms of mole ratio units is

The individual mass transfer co-efficients (moles/m2 . s) for absorption of a solute from a gas mixture into a liquid solvent are, KL = 4.5 and KG = 1.5. The slope of the equilibrium line is 3. Which of the following resistance (s) is (are) controlling?

Pore size of the molecular seive 5A is __________ mm.

Swenson-Walker crystalliser is a __________ unit

According to the Fenske equation, what will be the minimum number of plates required in a distillation column to separate an equimolar binary mixture of components A and B into an overhead fraction containing 99 mol% A and a bottom fraction containing 98 mol% B ? Assume that relative volatility (αAB = 2) does not change appreciably in the coloumn.

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

With increase in temperature, the mutual solubility of two liquids

Pick out the wrong statement.

The relative volatility of a binary mixture at the azeotropic composition is

Relative volatility varies with the concentration of component for an ideal solution. The relative volatity of a binary mixture may be defined as the ratio of vapor pressure of component 'A' to that of component 'B', when

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

Lewis number (Le) is

Which of the following is not a continuous leaching equipment?

__________ extractor is used for the concentration of radioactive nuclear waste.

Moisture content of a substance when at equilibrium with a given partial pressure of the vapour is called the __________ moisture.

All moisture in a non-hygroscopic material is the __________ moisture.

Pick out the correct relationship. (where, Ri = internal reflux ratio Ro = external reflux ratio.)

Separation of __________ employs gaseous diffusion process.

For water-ethanol system, the minimum reflux ratio

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)

Though, theoretically the adsorption & desorption isotherms is expected to coincide but sometimes at least a part of the isotherms does not coincide and this phenomenon is known as adsorption hysterisis. In such cases, the desorption equilibrium pressure is __________ that obtained for adsorption.

Experimental determination of __________ is done by wetted wall column method.

Pick out the wrong statement:

In liquid extraction, if the selectivity is unity, then

Paper industry employs __________ driers.

Which of the following has the same dimension as mass diffusivity?

Pick out the wrong statement pertaining to the cooling towers.

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

Leaching of coarse solid lumps is also termed as

The main reason for dividing a tall packed tower into series of small towers is to

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?

Measurement of the interfacial area of mass transfer is achieved easily & accurately in case of a __________ coloumn.

With the lowering of equiliDrium pressure, at a given temperature, the amount of ad-sorbate on the adsorbent

Mass transfer co-efficient is defined as

When an unsaturated air-water mixture is heated at constant pressure, then

During sensible cooling process

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

In case of physical adsorption, the difference between heat of adsorption and heat of normal condensation is

Pick out the wrong statement:

The value of L/mG ratio for economical absorption operation ranges from

Large scale usage of flash distillation is practised in

High pressure at the bottom of a distillation tower handling heat sensitive materials results in

Alcohol is dehydrated using __________ distillation.

Separation of two volatile liquids by distillation makes use of their

Which of the following increases during evaporative cooling process with recirculated water supply?

Dried finished product sampled from various parts of a __________ dryer exhibits non-uniformity in the moisture content.

__________ is used as an 'entrainer' for the separation of acetic acid-water mixture by distillation.

Rotary dryers cannot handle __________ materials.

Pick out the correct statement.

An example of elution is

The operating line for an absorber is curved, when plotted in terms of

Relative volatility does not change appreciably with the change in

Boiling point diagram is not affected by the ambient

The dew point of a saturated gas phase equals the __________ temperature.

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

In case of liquid-liquid binary diffusion, diffusivity of one constituent into another is not dependent on the

For continuous drying of grannular or crystalline material, the dryer used is the __________ dryer.

When adsorption hysteresis is observed, the desorption equilibrium pressure is __________ that obtained by adsorption.

Moisture in a substance exerting an equilibrium vapour pressure less than that of pure liquid at the same temperature is called the __________ moisture.

For a binary mixture with low relative volatility, continuous rectification to get pure products will require

The efficiency of a plate column will be maximum, when the flow is ideal __________ the plate.

Heat load in a cooling tower

In case of absorption with exothermic reaction, for fluids having

Detergent solution is dried to a powder in a

Which of the following mixtures does not form an azeotrope at atmosheric pressure?

During bottling of cold drinks (e.g. Pepsi), the main resistance to mass transfer for the absorption of carbon dioxide in water lies in the

The overall mass transfer co-efficient for the absorption of SO2 in air with dilute NaOH solution can be increased substantially by

Flooding results in

For the air water system under ambient conditions, the adiabatic saturation temperature and the wet bulb temperature are nearly equal, because

In an operating distillation column, the

In a forced draft cooling tower, water is cooled from 95 to 80°F by exposure to air with a wet bulb temperature of 70°F. In this case, the

The diffusivity (D) in a binary gas mixture is related to the temperature (T) as

For which of the following unit operations, Lewis number is of significance?

Tray spacing in a distillation column of dia 10-12 ft. used in petroleum refinery may be around __________ inches.

If a1 and a2 are the relative volatilities when the pressure in the distillation column is 1 and 2 atm respectively. Pick out the correct statement.

The dimension of diffusivity is same as that of the

The temperature to which a vapour gas mixture must be cooled (at varying humidity) to become saturated is called the __________ temperature.

Entrainer used in azeotropic distillation should

In case of steam distillation, the steam leaving the liquid is not completely saturated with distillate vapour, because

Pick out the wrong statement.

Leaching of coffee from coffee beans is done by

For contacting a highly soluble gas with a liquid

During drying operation, it is easier to remove the __________ moisture.

With increase in solvent rate, the number of transfer units, NtoG, for a fixed degree of absorption from a fixed amount of gas

Ion exchange process is similar to

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,

Dryer widely used in a textile industry is __________ dryer.

Solvent used in extractive distillation

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

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)

The vapour pressure exerted by the moisture contained in a wet solid depends upon the

The absorption factor is defined as (where, L = liquid flow rate, G = gas flow rate and, m = slope of the equilibrium line)

Smoke is an example of

Which of the following adsorbant is used in the refinning of sugar?

Stacked packing compared to dumped packing

In McCabe-Thiele method of theoretical plate calculation for a distillation column, the operating lines of stripping and rectifying sections coincide with the diagonal at __________ reflux.

Which of the following parameters remains constant during chemical dehumidification?

Drying of a solid involves __________ transfer.

Mechanism of moisture removal in case of freeze drying of food stuff is by

The dew point of an unsaturated gas-vapor mixture does not depend upon the __________ of the mixture.

Which is not concerned directly with mass transfer?

Removal of __________ exemplifies an adsorption unit operation.

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

With increase in the mass velocity of the gas, the rate of drying during the constant rate period __________ , if the conduction and radiation through the solid are negligible.

For gas absorption, low viscosity solvents are preferred, because of their

To remove all the moisture from a wet solid it requires exposure to __________ air.

The operating cost of a distillation column at minimum reflux ratio is

The reflux to a distillation column is 100 moles/hr, when the overhead product rate is 50 moles/hr. The reflux ratio is

Molecular diffusivity of a liquid

The wet and 'dry bulb temperature for a vapour-gas mixture are 25°C and 30°C respectively. If the mixture is heated to 45°C at constant pressure, the wet bulb temperature will be __________ °C.

Henry's law states that the

Ammonia present in the coke oven gas is removed by washing with

With increase in temperature, the leaching rate increases due to

Which of the following processes is not an example of adsorption applied to gaseous separations?

The critical moisture content in case of drying indicates the __________ rate period.

Pick out the wrong statement

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

For a binary mixture distillation process, the degree of freedom is 2. However, if the pressure is fixed in this process, the number of independent variables in this process will be

H2S is being absorbed in a gas absorber unit. The height of the transfer unit based on the overall mass transfer coefficient on the gas side is 0.4 m. The equilibrium data is given by, y = 1.5 x. The bulk concentration of H2S has to be reduced from 0.05 to 0.001 mole fraction in the gas side. The height of the tower (in metres) corresponding to an operating line given by, y = 5x + 0.001 is

Packed column distillation is limited to the column __________ metres.

For the flow of gases through a capillary, with increase in temperature, the permeability __________ as per Knudsen law.

Which of the following is directly concerned with psychrometry?

Plate efficiency in a distillation column is reduced due to the __________ of liquid.

The most efficient cooling tower out of the following is

Sodium bicarbonate is produced during soda ash manufacture using a __________ tower.

Powdery materials can be guarded against caking tendency on storage by

In case of cooling towers, the ratio of the rates of heat and mass transfer is indicated by the __________ number.

Which one of the following devices is not used for both the absorption as well as the liquid-liquid extraction processes?

The temperature of water cooled in cooling tower is always __________ temperature of entering air.

Which of the following processes is followed by unsaturated air (with dry bulb temperature 12°C and relative humidity 47%) passing through water spray washer (temperature of water being constant at 40°C?

Mass transfer co-efficient is directly proportional to DAB according to the __________ theory.

The relative volatility of a binary mixture at constant temperature __________ the total pressure.

Tower diameter may be decreased by

Rayleigh's equation applies to __________ distillation.

Steady state equimolal counter diffusion is encountered in

Which of the following is considered equivalent to one theoretical stage in Mc-Cabe Thiele's method?

Polar organic compounds are normally used as separating agents for the azeotropic and extractive distillation. Which of the following is the most important factor to be considered for the choice of the separating agent for extractive distillation?

As the reflux ratio increases, the slope of the operating line for rectifying section

Cox chart, which is useful in the design of distillation column particularly for petroleum hydrocarbons, is a plot of (where, P = vapor pressure, T = temperature)

The unit of volumetric diffusivity is

For a ternery mixture, in which equilateral triangular co-ordinate is used in leaching and extraction, a __________ of the equilateral triangular co-ordinates.

Steady state temperature reached by a small amount of liquid evaporating into a large amount of unsaturated vapour-gas mixture is called the __________ temperature.

The Reynolds number of the liquid was increased 100 fold for a laminar falling film used for gas-liquid contacting. Assuming penetrating theory is applicable, the fold increase in the mass transfer co-efficient (Kc) for the same sytem is

The slope of 9-line is determined by the

In steam distillation, the

Which of the following can be calculated theoretically using steam table and Dalton's law of partial pressure; if the relative humidity and dry bulb temperature of moist air is known?

Steam distillation is used for separation of high boiling

The feed to fractionating column is changed from saturated vapour to saturated liquid. If the separation and reflux ratio remains unchanged, the number of ideal stages will

Rose oil is extracted from rose leaves using __________ distillation.

Hypersorption refers to a __________ process.

Which of the following is the correct ternery diagram for liquid-liquid extraction system comprising of two pairs partly soluble (e.g., chlorobenzene-water-methyl ethyl ketone system)?

Extraction of coffee from its seed is done by

In azeotropic mixture, the equilibrium vapour composition is

With lapse of time, the overhead composition of light component in case of batch distillation with constant reflux

Lewis number, which is important in problems involving simultaneous heat and mass transfer, is the ratio of

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

Dry bulb temperature of the gas is __________ the wet bulb temperature.

Decoction refers to the use of solvent

Flash distillation is suitable for separating the constituents of a binary system, which

The ratio of Murphree plate efficiency to point efficiency is 1 in a __________ flow model.

The rough value of diffusion co-efficient of water vapor into air at 25°C may be about __________ cm2/sec.

Flooding in a column results due to

Which of the following gas-liquid contacting devices incurs the least pressure drop for a particular duty?

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?

Unsaturated air (with dry bulb temperature and dew point being 35°C and 18°C respectively) is passed through a water spray chamber maintained at 15°C. The air will be cooled

The process employing desorption of the absorbed solute by a solvent is called

If the overall efficiency and Murphree plate efficiency are equal, then both the equilibrium and operating lines are

Which of the following operations does not involve leaching?

The recovery of pencillin from the acidified fermentation broth is done by

Unit operation involved in the prilling of urea is

Molecular seives are porous

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

A binary mixture of benzene and cyclohexane is separated by

Component A is diffusing in a medium B. The flux NA relative to a stationary point is equal to the flux due to molecular difusion, if

Cox chart is useful in the design of

Dew point of an air-water vapor mixture

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

The solvent used in liquid-liquid extraction should have __________ less than one.

The suitable evaporator for concentration of foaming liquids is a __________ evaporator.

The ratio of Murphree plate efficiency to point efficiency is always > 1 in a __________ flow model.

Tea percolation employs

Which of the following assumes constant molal vaporisation and overflow?

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

Selectivity of the solvent used in solvent extraction should be

Pick out the wrong statement pertaining to leaching.

Wet bulb and dry bulb temperatures becomes identical at __________ percent saturation curve.

NSc/NPr is called the

McCabe-Thiele method

The film penetration model of mass transfer was enunciated by

The most economical range of absorption factor is

Channelling is most severe

Out of two equilibrium curves, first one lies above the diagonal and the second lies below the diagonal in the x-y plot. It means that separation by distillation is

ADDUCTS' and 'CLATHRATES' are used in case of

Adsorption is an unit operation which generally involves __________ systems.

In case of __________ distillation, a solvent is added to alter the relative volatility of the mixture to be separated.

Separation of the isotopes of helium for scientific investigations is done by

In a binary system, separation is very efficient, when the relative volatility is

Fenske-Underwood equation used for calculating the minimum number of theoretical plates in distillation column is valid for

The binary diffusivity in gases does not depend upon the

Berl saddle made of carbon cannot be used for

1 kg of a saturated aqueous solution of a highly soluble component A at 60°C is cooled to 25°C. The solubility limits of A are (0.6 kgA/kg water) at 60°C and (0.2 kgA/kg water) at 25°C. The amount in kg of the crystals formed is

During drying of a solid, the critical moisture content increases with

Priming in a distillation column

The commonly used solvent in supercritical extraction is

When the liquid over a plate is of uniform concentration, then

In saturated gas, the

As per Gilliland's equation, the diffusivity is

Pick out the wrong statement.

A mixture of 10% C6H6 vapour in air at 25°C and 750 mm Hg has a dew point of 20°C. Its dew point at 30°C and 700 mm Hg will be around __________ °C.

Which of the following is not fixed by the process requirements, in the design of absorbers?

If the amount of the steam used in steam distillation is increased, the temperature of distillation

Moisture in a solid exerting an equilibrium vapour pressure equal to that of the pure liquid at the same temperature is called the __________ moisture.

Inside the distillation columns, the

When the psychometric ratio is __________ then the adiabatic saturation temperature and wet bulb temperature becomes equal.

Desirable value of absorption factor in an absorber is

Refractory bricks are usually dried in a __________ dryer.

For __________ drying, the effects of velocity, temperature and humidity of the gas and the thickness of the solid are the same.

What is the degree of freedom of an absorption process in which only one component is transferred between phases?

Sticky material can be dried in a __________ dryer.

Langmuir equation is associated with

During the constant rate period of drying of a solid,

At a fixed total pressure, humidity depends only on the

If moisture content of solid on dry basis is X, then the same on wet basis is

Flash distillation is

__________ developed the film theory.

For absorbers, high pressure drop results in

Which of the following parameters remains almost constant during adiabatic saturation of unsaturated air?

Coffee is prepared from coffee beans by leaching with

Gaseous diffusion co-efficient increases with increase in the

With increase in absolute humidity, the dew point of an unsaturated mixture of air and water vapor (at constant pressure and temperature)

If xD = overhead product molal composition and RD = reflux ratio, then slope and intercept of the operating line for rectifying section are respectively

Pick out the wrong statement. Raoult's law does not apply, when the

Water-ethyl alcohal solution can be concentrated (in respect of alcohal concentration) by __________ distillation.

L/mG is the expression for

Extraction of pencillin employs a __________ extraction coloumn.

In case of gases, the binary diffusivity is proportional to (where, P = pressure)

When the gas to be dissolved in liquid is a/an __________ then normally co-current adsorber are used.

Corresponding to Prandtl number in heat transfer, the dimensionless group in mass transfer is the __________ number.

If a two phase system is in physical equilibrium; then it means that, the

McCabe-Thiele method of binary distillation does not assume that the

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

The Hatta number is important in

When a multistage tray tower uses a minimum reflux ratio, it implies

CO2 can be absorbed by

For the same process conditions, the reflux ratio of an unlagged distillation column

An ideal tower packing should not

Which of the following is a suitable absorbent for removal of H2S from natural gas?

Acetone is to be removed from air in an isothermal dilute absorber using pure water as solvent. The incoming air contains 5 mole% of acetone (yin = 0.05). The design equation to be used for obtaining the number of trays (N) of the absorber is, N+2 = 6 log (yin/yout).For 98% recovery of acetone, the number of trays required is/are

Schimdt number and Lewis number for pure air at atmospheric conditions are respectively

Below is given an equilibrium moisture curve of a substance. State which regions represent free moisture and unbound moisture respectively. https://www.indiabix.com/_files/images/chemical-engineering/mass-transfer/292-170-1.png

Molecular diffusion is caused by the

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

Separation of a mixture of two gases by absorption in the liquid solvent depends upon the difference in their

Components, having widely different boiling point in a binary mixture, can be separated using __________ distillation.

Which of the following equipments is not used in liquid-liquid extraction?

Pick out the wrong statement.

Equilibrium-moisture curves of different solids

Azeotropism for ethyl alcohol-water system disappears by

Degree of freedom for leaching and solvent extraction process is

Diffusion co-efficient generally depends upon the temperature, pressure & the nature of the components of the system. Its dimension is not the same as that of the

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?

In the absorption of ammonia in water, the main resistance to absorption is by the __________ phase.

Drying of refractory is normally carried out in a __________ dryer.

The expression, ln(F/W) = https://www.indiabix.com/_files/images/chemical-engineering/mass-transfer/314-454-1.png is

Heat sensitive materials with very high latent heat of vaporisation may be economically separated using

When the solvent dissolves very little of solute, then

An alkaline solution is used to reduce the concentration of carbon dioxide in a stream from 10% to 0.1% by absorption with irreversible chemical reaction. The overall number of transfer units based on gas phase is

HETP is numerically equal to HTU, only when the operating line

In a distillation operation, what is the effect of the temperature of the reflux stream (given below) on the condenser and reboiler loads ? Reflux conditions: (i) Reflux stream is completely liquid and is at its bubble point. (ii) Reflux stream is below its bubble point.

Steady state equimolal counter diffusion occurs in case of

JD factor for mass transfer is a function of Reynolds number. Mass transfer by molecular diffusion from a single drop to surrounding still air is given by

The relative saturation of an unsaturated mixture of gas and vapor is independent of the

The adiabatic saturation curve for a vapour-gas mixture is

Pick out the wrong statement.

The value of NA/(NA + NB), for steady state equimolal counter diffusion of two gases 'A' and 'B' is

Drift in a cooling tower is

With increase in the concentration of the adsorbate, the integral heat of adsorption

Small dia distillation column can be a

If mass diffusivity in a mixture is equal to the thermal diffusivity, then the Lewis number is

An air-water vapour mixture has a dry bulb temperature of 60°C and a dew point temperature of 40°C. The total pressure is 101.3 kPa and the vapour pressure of water at 40°C and 60°C are 7.30 kPa and 19.91 kPa respectively.The humidity of air sample expressed as kg of water vapour/kg of dry air is

__________ column is used in gas absorption process.

Nitrobenzene (boiling point = 210.6°C) is steam distilled at 1 atm pressure.Nitrobenzene will distill off __________ °C.

Pick out the wrong statement.

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

Batch tray dryers suffers from the disadvantage of

In a moderately sized packed absorption tower, channeling (which is most severe with stacked packings) can be minimised by taking the ratio of tower diameter to packing diameter

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

The 'shanks system' of leaching (i.e., counter-current multiple contact leaching) is used for

Penetration model (theory) for mass transfer was enunciated by

Surface renewal model of mass transfer was enunciated by

When the __________ the relative humidity of air decreases, despite an increase in the absolute humidity.

For turbulent mass transfer in pipes, the Sherwood number depends on the Reynolds number as

The relative humidity of air decreases in-spite of an increase in the absolute humidity, when the

Unit of molal diffusivity is

The term "approach" in a cooling tower refers to the difference in the temperature of the

Binary distillation involves the mass transfer by __________ at the gas-liquid interface.

In a gas-liquid absorption coloumn, for obtaining the maximum absorption efficiency

Reverse osmosis is also called

Which of the following is not a batch drier?

Steam distillation is not recommended to be used, if the

Rayleigh equation applies to __________ distillation.

Mass transfer co-efficient 'K' according to penetration theory varies with mass dif-fusivity as

Most important factor to be considered in the selection of packings for absorbers is the __________ of packing.

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

The relative saturation of a partially saturated mixture of vapour and gas can be increased by __________ of the mixture.

Danckwerts developed the __________ theory.

Molecular distillation is

Drying of a wet solid under constant drying conditions means the exposure of the wet solid to the air of constant

Which of the following provides maximum contact surface for a liquid-vapour system?

For experimental determination of mass transfer co-efficient by wetted wall tower, the mass transfer area is

In stripping section of continuous distillation column, the

Molality is defined as the number of gm moles of solute per __________ of solvent.

__________ is concerned with the adsorption equilibria.

Which of the following is the correct ternery diagram for liquid-liquid extraction system comprising of one pair partly soluble (e.g. water-benzene-acetic acid in which A-diluent, B - solvent and C - solute)?

Fractional solvent extraction

In the layout plan for a vacuum distillation unit, operating at 60 mm Hg, supported by a barometric condenser, the appropriate place for the location of vacuum drum for collecting the distillate will be

Raschig ring made of procelain cannot be used for treating concentrated

H2S present in naphtha reformed gas is removed by absorbing with

During constant rate drying period, vaporisation rate per unit drying surface area

Pick out the wrong statement.

In rectifying section of a continuous distillation column, the

For a fixed number of ideal stages in a distillation column, as the reflux ratio is increased, the difference in composition between the top and bottom product streams

According to Chilton-Colburn analogy for mass transfer, NSt.NSc2/3 is equal to

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

Minimum reflux ratio in a distillation column results in

Flooding in a distillation column is detected by a sharp

In extraction, as the temperature increases, the area of hetrogeneity (area covered by binodal curve)

Pick out the wrong statement.

In case of an unsaturated mixture of gas and vapor, the percentage saturation is __________ its relative saturation.

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

For a single component absorber, the operating line is straight only when plotted in term of __________ units.

In case of unsaturated air

For a binary mixture with low relative volatility,

Plate efficiency

Absorption accompanied by heat evolution results in

Even though bubble cap towers are very effective for humidification operation, they are not used commonly in industries, because of the

For a distillation column operating at minimum reflux, the

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))

Flash distillation is suitable for the separation of components

In Mcabe-Thiele method, at infinite reflux ratio

Leaching rate is independent of the

Use of packed towers for distillation is generally limited to the

Pick out the wrong statement.

Which of the following decreases during evaporative cooling process with recirculated water supply?

Laboratory determination of the dif-fusivity of vapor is done by __________ method.

The minimum liquid rate to be used in an absorber corresponds to an operating line

In a gas-liquid absorption coloumn, for obtaining the maximum absorption efficiency

Reverse osmosis is also called

Which of the following is not a batch drier?

Steam distillation is not recommended to be used, if the

Rayleigh equation applies to __________ distillation.

Mass transfer co-efficient 'K' according to penetration theory varies with mass dif-fusivity as

Most important factor to be considered in the selection of packings for absorbers is the __________ of packing.

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

The relative saturation of a partially saturated mixture of vapour and gas can be increased by __________ of the mixture.

Danckwerts developed the __________ theory.

Molecular distillation is

Drying of a wet solid under constant drying conditions means the exposure of the wet solid to the air of constant

Which of the following provides maximum contact surface for a liquid-vapour system?

For experimental determination of mass transfer co-efficient by wetted wall tower, the mass transfer area is

In stripping section of continuous distillation column, the

Molality is defined as the number of gm moles of solute per __________ of solvent.

__________ is concerned with the adsorption equilibria.

Fractional solvent extraction

Raschig ring made of procelain cannot be used for treating concentrated

H2S present in naphtha reformed gas is removed by absorbing with

During constant rate drying period, vaporisation rate per unit drying surface area

Pick out the wrong statement.

In rectifying section of a continuous distillation column, the

For a fixed number of ideal stages in a distillation column, as the reflux ratio is increased, the difference in composition between the top and bottom product streams

According to Chilton-Colburn analogy for mass transfer, NSt.NSc2/3 is equal to

Minimum reflux ratio in a distillation column results in

Flooding in a distillation column is detected by a sharp

In extraction, as the temperature increases, the area of hetrogeneity (area covered by binodal curve)

Pick out the wrong statement.

In case of an unsaturated mixture of gas and vapor, the percentage saturation is __________ its relative saturation.

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

For a single component absorber, the operating line is straight only when plotted in term of __________ units.

In case of unsaturated air

For a binary mixture with low relative volatility,

Plate efficiency

Absorption accompanied by heat evolution results in

Even though bubble cap towers are very effective for humidification operation, they are not used commonly in industries, because of the

For a distillation column operating at minimum reflux, the

Flash distillation is suitable for the separation of components

In Mcabe-Thiele method, at infinite reflux ratio

Leaching rate is independent of the

Use of packed towers for distillation is generally limited to the

Pick out the wrong statement.

Which of the following decreases during evaporative cooling process with recirculated water supply?

Laboratory determination of the dif-fusivity of vapor is done by __________ method.

The minimum liquid rate to be used in an absorber corresponds to an operating line