The diffusivity, DAB (for component A diffusing in B) is equal to the diffusivity Dsub>BA (for component B diffusing in A) for a binary mixture of
The diffusivity, DAB (for component A diffusing in B) is equal to the diffusivity Dsub>BA (for component B diffusing in A) for a binary mixture of
Overall efficiency of the distillation column is
Overall efficiency of the distillation column is
The most economical range of absorption factor is
The most economical range of absorption factor is
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
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
Which of the following equipments is not used in liquid-liquid extraction?
Which of the following equipments is not used in liquid-liquid extraction?
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)
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)
Degree of freedom for leaching and solvent extraction process is
Degree of freedom for leaching and solvent extraction process is
Packed column distillation is limited to the column __________ metres.
Packed column distillation is limited to the column __________ metres.
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
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
__________ column is the most suitable for achieving the best performance for mass transfer operations involving liquid with dispersed solids.
__________ 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
Absorption factor, for a fixed degree of absorption from a fixed amount of gas should be
__________ is the temperature at which a gas-vapor mixture becomes saturated, when cooled at constant total pressure out of contact with a liquid.
__________ is the temperature at which a gas-vapor mixture becomes saturated, when cooled at constant total pressure out of contact with a liquid.
Channelling in a packed tower results from the
Channelling in a packed tower results from the
With increase in temperature, the solubility of gases in liquids, at fixed pressure
With increase in temperature, the solubility of gases in liquids, at fixed pressure
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
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
Experimental determination of __________ is done by wetted wall column method.
Experimental determination of __________ is done by wetted wall column method.
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.
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.
For continuous drying of grannular or crystalline material, the dryer used is the __________ dryer.
For continuous drying of grannular or crystalline material, the dryer used is the __________ dryer.
In case of an absorber, the operating
In case of an absorber, the operating
Freundlich equation applies to the adsorption of solute from
Freundlich equation applies to the adsorption of solute from
For a binary mixture with low relative volatility,
For a binary mixture with low relative volatility,
The assumption made in Elis method in distillation is that enthalpy concentration lines of vapor and liquid are
The assumption made in Elis method in distillation is that enthalpy concentration lines of vapor and liquid are
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 )
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 )
The ratio of Murphree plate efficiency to point efficiency is always > 1 in a __________ flow model.
The ratio of Murphree plate efficiency to point efficiency is always > 1 in a __________ flow model.
__________ extractor is used for the concentration of radioactive nuclear waste.
__________ extractor is used for the concentration of radioactive nuclear waste.
The diffusion co-efficient in m² /s. of acetic acid in benzene (liquid in liquid) is
The diffusion co-efficient in m² /s. of acetic acid in benzene (liquid in liquid) is
Advantage of continuous drying over batch drying is that the
Advantage of continuous drying over batch drying is that the
The most efficient cooling tower out of the following is
The most efficient cooling tower out of the following is
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
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
Which of the following employs an accessory known as 'drift eliminator' ?
Which of the following employs an accessory known as 'drift eliminator' ?
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.
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 reflux to a distillation column is 100 moles/hr, when the overhead product rate is 50 moles/hr. The 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
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.
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.
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?
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?
Flooding in a distillation column is detected by a sharp
Flooding in a distillation column is detected by a sharp
Ponchan-Savarit method analyses the fractional equipment based on
Ponchan-Savarit method analyses the fractional equipment based on
The cooling effect in a cooling tower can not be increased by
The cooling effect in a cooling tower can not be increased by
The relative saturation of a partially saturated mixture of vapour and gas can be increased by __________ of the mixture.
The relative saturation of a partially saturated mixture of vapour and gas can be increased by __________ of the mixture.
Pick out the wrong statement pertaining to the analogy between equations of heat and mass transfer operations.
Pick out the wrong statement pertaining to the analogy between equations of heat and mass transfer operations.
The recovery of pencillin from the acidified fermentation broth is done by
The recovery of pencillin from the acidified fermentation broth is done by
Even though bubble cap towers are very effective for humidification operation, they are not used commonly in industries, because of the
Even though bubble cap towers are very effective for humidification operation, they are not used commonly in industries, because of the
The boiling points of pure components of a binary system __________ with increase in total pressure of the system.
The boiling points of pure components of a binary system __________ with increase in total pressure of the system.
Weight of 1 m³ of humid air as compared to 1 m³ of dry air, under the same conditions, is
Weight of 1 m³ of humid air as compared to 1 m³ of dry air, under the same conditions, is
Dew point of a gas-vapour mixture
Dew point of a gas-vapour mixture
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)
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)
Dryer widely used in a textile industry is __________ dryer.
Dryer widely used in a textile industry is __________ dryer.
Calculation of mass transfer co-efficient is mostly/normally done using __________ theory.
Calculation of mass transfer co-efficient is mostly/normally done using __________ theory.
In case of a desorber (stripper), the
In case of a desorber (stripper), the
In continuous distillation, the internal reflux ratio (Ri) and the external reflux ratio (Re) are related as
In continuous distillation, the internal reflux ratio (Ri) and the external reflux ratio (Re) are related as
Which is not concerned directly with mass transfer?
Which is not concerned directly with mass transfer?
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?
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?
Critical humidity of a solid salt means the humidity
Critical humidity of a solid salt means the humidity
Which of the following binary systems is an example of a maximum boiling azeotrope?
Which of the following binary systems is an example of a maximum boiling azeotrope?
Humid volume is the total volume in m³ of 1 kg of
Humid volume is the total volume in m³ of 1 kg of
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)
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)
'Absorption with chemical reaction' is involved in the removal of
'Absorption with chemical reaction' is involved in the removal of
Coffee is prepared from coffee beans by leaching with
Coffee is prepared from coffee beans by leaching with
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
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
Psychrometry deals with the properties of gas-vapor mixture. Humidity can be determined by the measurement of the __________ of a fibre.
Psychrometry deals with the properties of gas-vapor mixture. Humidity can be determined by the measurement of the __________ of a fibre.
The ratio of Murphree plate efficiency to point efficiency is 1 in a __________ flow model.
The ratio of Murphree plate efficiency to point efficiency is 1 in a __________ flow model.
For ethanol-water system, the lowering of distillate quality from 95% to 92% will cause __________ plate requirement.
For ethanol-water system, the lowering of distillate quality from 95% to 92% will cause __________ plate requirement.
Dew point of an air-water vapor mixture
Dew point of an air-water vapor mixture
Leaching of coarse solid lumps is also termed as
Leaching of coarse solid lumps is also termed as
Laboratory determination of the dif-fusivity of vapor is done by __________ method.
Laboratory determination of the dif-fusivity of vapor is done by __________ method.
Mass transfer rate between two fluid phases does not necessarily depend on the __________ of the two phases.
Mass transfer rate between two fluid phases does not necessarily depend on the __________ of the two phases.
Which of the following is directly concerned with psychrometry?
Which of the following is directly concerned with psychrometry?
The reciprocal of stripping factor is termed as
The reciprocal of stripping factor is termed as
According to Poiseuille's law, the permeability for gas flow through a capillary is proportional to (where, μ = gas viscosity)
According to Poiseuille's law, the permeability for gas flow through a capillary is proportional to (where, μ = gas viscosity)
The overall mass transfer co-efficient for the absorption of SO₂ in air with dilute NaOH solution can be increased substantially by
The overall mass transfer co-efficient for the absorption of SO₂ in air with dilute NaOH solution can be increased substantially by
If f = moles of vapour present per mole of feed, then the slope of feed line is (Mcabe-Thiele method)
If f = moles of vapour present per mole of feed, then the slope of feed line is (Mcabe-Thiele method)
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
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
Powdery materials can be guarded against caking tendency on storage by
Powdery materials can be guarded against caking tendency on storage by
Which of the following is the most suitable for extraction in a system having very low density difference?
Which of the following is the most suitable for extraction in a system having very low density difference?
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With increase in temperature, the leaching rate increases because of the
With increase in temperature, the leaching rate increases because of the
Which of the following is not fixed by the process requirements, in the design of absorbers?
Which of the following is not fixed by the process requirements, in the design of absorbers?
The 'shanks system' of leaching (i.e., counter-current multiple contact leaching) is used for
The 'shanks system' of leaching (i.e., counter-current multiple contact leaching) is used for
If moisture content of solid on dry basis is X, then the same on wet basis is
If moisture content of solid on dry basis is X, then the same on wet basis is
Removal of __________ exemplifies an adsorption unit operation.
Removal of __________ exemplifies an adsorption unit operation.
Which of the following equipments is not used for gas dispersion?
Which of the following equipments is not used for gas dispersion?
Pick out the correct statement.
Pick out the correct statement.
The relation, Sc = Pr = 1, is valid, when the mechanism of __________ ansfer is same.
The relation, Sc = Pr = 1, is valid, when the mechanism of __________ ansfer is same.
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
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
Measurement of the interfacial area of mass transfer is achieved easily & accurately in case of a __________ coloumn.
Measurement of the interfacial area of mass transfer is achieved easily & accurately in case of a __________ coloumn.
Pick out the wrong statement. Generally for physical adsorption, a gas of
Pick out the wrong statement. Generally for physical adsorption, a gas of
Drying of a solid involves __________ transfer.
Drying of a solid involves __________ transfer.
When the gas to be dissolved in liquid is a/an __________ then normally co-current adsorber are used.
When the gas to be dissolved in liquid is a/an __________ then normally co-current adsorber are used.
The solvent used in liquid extraction should not have high latent heat of vaporisation, because
The solvent used in liquid extraction should not have high latent heat of vaporisation, because
The equilibrium liquid composition compared to the vapor composition in case of azeotropic mixture is
The equilibrium liquid composition compared to the vapor composition in case of azeotropic mixture is
At a fixed total pressure, humidity depends only on the
At a fixed total pressure, humidity depends only on 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.
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.
HETP is numerically equal to HTU, only when the operating line
HETP is numerically equal to HTU, only when the operating line
In case of binary distillation, increasing the reflux ratio above optimum does not result in the increase of
In case of binary distillation, increasing the reflux ratio above optimum does not result in the increase of
Which of the following is an undesirable property in a tower packing?
Which of the following is an undesirable property in a tower packing?
For absorbers, high pressure drop results in
For absorbers, high pressure drop results in
Inside the distillation columns, the
Inside the distillation columns, the
In a gas-liquid absorption coloumn, for obtaining the maximum absorption efficiency
In a gas-liquid absorption coloumn, for obtaining the maximum absorption efficiency
The relative volatility of a binary mixture at the azeotropic composition is
The relative volatility of a binary mixture at the azeotropic composition is
The process employing desorption of the absorbed solute by a solvent is called
The process employing desorption of the absorbed solute by a solvent is called
The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are same for, NPr = NSc = __________
The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are same for, NPr = NSc = __________
Co-current absorbers are usually used when the gas to be dissolved in the liquid is
Co-current absorbers are usually used when the gas to be dissolved in the liquid is
Capacity of a rotary dryer depends on its
Capacity of a rotary dryer depends on its
Most important factor to be considered in the selection of packings for absorbers is the __________ of packing.
Most important factor to be considered in the selection of packings for absorbers is the __________ of packing.
