Mass Transfer MCQs

Option A: Concentration of liquid and vapour leaving a plate will be same

Option B: Reflux ratio will be maximum

Option C: Number of plates required will be maximum

Option D: None of these

Correct Answer: Number of plates required will be maximum ✔

Option A: Thermal

Option B: Pressure

Option C: Concentration

Option D: Force

Correct Answer: Thermal ✔

Option A: Increases

Option B: Decreases

Option C: Remain unaffected

Option D: Passes through a maximum

Correct Answer: Increases ✔

Option A: Reducing the total pressure

Option B: Increasing the total pressure

Option C: Reducing the temperature

Option D: Both B. and C.

Correct Answer: D. Both B. and C. ✔

Option A: Substances from non-volatile impurities

Option B: Volatile impurity from still higher boiling substances

Option C: Both A. and B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. and B. ✔

Option A: -ve

Option B: +ve

Option C: 1

Option D: -1

Correct Answer: -ve ✔

Option A: Molar heats of vaporisation of components are nearly equal

Option B: Linear crystal growth rate depends on the degree of super-saturation

Option C: Linear crystal growth rate does not depend on the crystal size

Option D: Linear crystal growth rate depends on the crystal size

Correct Answer: Linear crystal growth rate does not depend on the crystal size ✔

Option A: Reduce the overall pressure drop

Option B: Avoid channelling

Option C: Reduce liquid hold-up

Option D: Avoid flooding

Correct Answer: Avoid channelling ✔

Option A: Reverse osmosis

Option B: Thermal diffusion

Option C: Leaching

Option D: Solvent extraction

Correct Answer: Thermal diffusion ✔

Option A: Having very close boiling points

Option B: Which form maximum boiling azeotrope

Option C: Having very wide boiling points

Option D: Which form minimum boiling azeotrope

Correct Answer: Having very wide boiling points ✔

A. f = 1
B. f 1
D. 0 < f < 1

Correct Answer: f = 1 ✔

Option A: f

Option B: f/2

Option C: 2f

Option D: 1/f

Correct Answer: f ✔

Option A: 100

Option B: 50

Option C: 78

Option D: None of these

Correct Answer: 100 ✔

Option A: Exponential

Option B: Parabolic

Option C: Linear

Option D: Cubic

Correct Answer: Exponential ✔

Option A: Not possible in the second case unless vacuum is applied

Option B: Not possible in the second case unless high pressure is applied

Option C: More readily done in the second case compared to first one

Option D: None of these

Correct Answer: More readily done in the second case compared to first one ✔

Option A: 0.5

Option B: 0.6

Option C: 1.0

Option D: 2.0

Correct Answer: 0.6 ✔

Option A: Thermal diffusion

Option B: Reverse osmosis

Option C: Adsorption

Option D: Absorption

Correct Answer: Reverse osmosis ✔

Option A: Is greater than

Option B: Is lower than

Option C: Is same as

Option D: Cannot be predicted as data are insufficient

Correct Answer: Is greater than ✔

Option A: Rotary

Option B: Cylinder

Option C: Drum

Option D: Freeze

Correct Answer: Rotary ✔

Option A: Wet bulb temperature

Option B: Partial pressure of water vapor

Option C: Relative humidity

Option D: None of these

Correct Answer: Wet bulb temperature ✔

Option A: Employs only one solvent

Option B: Employs two solvents

Option C: Results in low interfacial tension

Option D: None of these

Correct Answer: Employs two solvents ✔

Option A: Plug

Option B: Perfectly mixed

Option C: Both A. & B.

Option D: Neither A. nor B.

Correct Answer: Plug ✔

Option A: Increase in flow rate

Option B: Sharp drop in pressure drop

Option C: Sharp rise in pressure drop

Option D: None of these

Correct Answer: Sharp drop in pressure drop ✔

Option A: D0.5

Option B: D

Option C: 1/D

Option D: D1.5

Correct Answer: D0.5 ✔

Option A: Flash vaporisation

Option B: Extractive distillation

Option C: Solvent extraction

Option D: Ordinary distillation

Correct Answer: Extractive distillation ✔

Option A: Packing may be crushed due to thermal expansion/contraction of the components of the

Option B: Pressure drop in the equipment will be very high

Option C: Viscosity variation of the fluids may cause channelling/flooding

Option D: None of these

Correct Answer: A. Packing may be crushed due to thermal expansion/contraction of the components of the
equipments ✔

Option A: Absorption factor

Option B: Relative volatility

Option C: Selectivity

Option D: Murphree efficiency

Correct Answer: Relative volatility ✔

Option A: Number of plates is maximum

Option B: Overhead product is maximum

Option C: Both the operating lines coincide with the diagram

Option D: None of these

Correct Answer: Both the operating lines coincide with the diagram ✔

Option A: Increases tray efficiency

Option B: Provides large interfacial surface for mass transfer

Option C: Results due to very high gas velocity

Option D: Results due to very low gas velocity

Correct Answer: Results due to very low gas velocity ✔

Option A: Plug

Option B: Perfectly mixed

Option C: Both A. & B.

Option D: Neither A. nor B.

Correct Answer: Perfectly mixed ✔

Option A: Elution

Option B: Osmosis

Option C: Reverse osmosis

Option D: Sublimation

Correct Answer: Elution ✔

Option A: Is a function of the mass transfer between liquid and vapour

Option B: Increases due to foaming

Option C: Increases due to liquid entrainment

Option D: Increases due to weeping and dumping of liquid

Correct Answer: Is a function of the mass transfer between liquid and vapour ✔

Option A: 2

Option B: 8

Option C: 12

Option D: 18

Correct Answer: 2 ✔

Option A: Vapour is enriched with low boilers

Option B: Vapour is enriched with high boilers

Option C: Liquid is stripped of high boilers

Option D: None of these

Correct Answer: Vapour is enriched with high boilers ✔

Option A: Low pressure drop and high hold up

Option B: High pressure drop and low hold up

Option C: Low pressure drop and low hold up

Option D: High pressure drop and high hold up

Correct Answer: Low pressure drop and low hold up ✔

Option A: More than liquid composition

Option B: Less than liquid composition

Option C: Same as liquid composition

Option D: Independent of pressure

Correct Answer: Same as liquid composition ✔

Option A: Momentum flux

Option B: Kinematic viscosity

Option C: Thermal diffusivity

Option D: Both B. and C.

Correct Answer: D. Both B. and C. ✔

Option A: Wet bulb temperature

Option B: Relative humidity

Option C: Partial pressure of vapour

Option D: None of these

Correct Answer: None of these ✔

Option A: 90

Option B: 91.5

Option C: 95

Option D: 99

Correct Answer: 95 ✔

Option A: 15 min

Option B: 51 min

Option C: 71 min

Option D: 94 min

Correct Answer: 71 min ✔

Option A: Azeotropic mixture is to be separated and the final product is miscible with water

Option B: Liquids decompose, if distilled directly at atmospheric pressure

Option C: Material cannot be distilled by indirect heating even under low pressure, because of the high

Option D: Material to be distilled is thermally unstable or has the tendency to react with other

Correct Answer: Azeotropic mixture is to be separated and the final product is miscible with water ✔

Option A: Partial condenser

Option B: Total condenser

Option C: Reboiler

Option D: Both B. and C

Correct Answer: D. Both B. and C ✔

Option A: Decrease in air temperature

Option B: Increase in air humidity

Option C: Both A. and B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. and B. ✔

Option A: Height < 6

Option B: Diameter < 0.6

Option C: Both A. & B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. & B. ✔

Option A: Solids are drained to the same extent

Option B: Ratio of the insoluble to solution is constant

Option C: Both A. & B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. & B. ✔

Option A: μ

Option B: 1/μ

Option C: √μ

Option D: μ2

Correct Answer: μ ✔

Option A: High evaporation losses of water

Option B: High pressure drop of the gas

Option C: Difficulty in its fabrication

Option D: None of these

Correct Answer: High pressure drop of the gas ✔

Option A: (1 + Ro) = Ro/Ri

Option B: (1 – Ro) = Ro/Ri

Option C: (1 + Ri) = Ro/Ri

Option D: (1 – Ri) = Ro/Ri

Correct Answer: (1 + Ro) = Ro/Ri ✔

Option A: Temperature at constant humidity

Option B: Humidity at constant temperature

Option C: Both A. and B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. and B. ✔

Option A: Using higher reflux ratio

Option B: Use of increased tray spacing

Option C: Increasing the liquid flow rate

Option D: Increasing the vapour flow rate

Correct Answer: Use of increased tray spacing ✔

Option A: Hydrochloric acid

Option B: Nitric acid

Option C: Alkalis

Option D: Sulphuric acid

Correct Answer: Alkalis ✔

Option A: Humidity

Option B: Temperature

Option C: Both A. & B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. & B. ✔

Option A: Increases with temperature

Option B: Decreases with temperature

Option C: May increase or decrease with temperature

Option D: Is independent of temperature

Correct Answer: Increases with temperature ✔

Option A: 100

Option B: 0

Option C: 50

Option D: Between 0 and 100

Correct Answer: 0 ✔

Option A: Free

Option B: Equilibrium

Option C: Unbound

Option D: Bound

Correct Answer: Unbound ✔

Option A: 1

Option B: ∞

Option C: 0.5

Option D: 2

Correct Answer: 1 ✔

Option A: High temperature distillation

Option B: For heat-sensitive materials

Option C: Very low pressure distillation

Option D: Both B. and C.

Correct Answer: D. Both B. and C. ✔

Option A: Induced draft

Option B: Forced draft

Option C: Natural draft

Option D: Atmospheric

Correct Answer: Induced draft ✔

Option A: Minimise the overall pressure drop

Option B: Avoid flooding

Option C: Reduce liquid hold up

Option D: Avoid channelling

Correct Answer: Avoid channelling ✔

Option A: Solvent extraction

Option B: Continuous distillation

Option C: Evaporation

Option D: Absorption

Correct Answer: Solvent extraction ✔

Option A: Truck drier

Option B: Agitated pan drier

Option C: Fluidised bed drier

Option D: Vacuum shelf drier

Correct Answer: Fluidised bed drier ✔

Option A: 2

Option B: 0.5

Option C: 50

Option D: 150

Correct Answer: 2 ✔

Option A: Less than

Option B: More than

Option C: Equal to

Option D: Either A. or B.; depends on the solid

Correct Answer: Less than ✔

Option A: Diffusivity of solute increases

Option B: Viscosity of solvent decreases

Option C: Thermal conductivity of solute increases

Option D: None of these

Correct Answer: Diffusivity of solute increases ✔

Option A: Agitation

Option B: Temperature

Option C: Particle size

Option D: None of these

Correct Answer: None of these ✔

Option A: Plate

Option B: Baffle

Option C: Packed

Option D: None of these

Correct Answer: Baffle ✔

Option A: Increasing the air velocity over the wet surfaces

Option B: Reducing the humidity of entering air

Option C: Lowering the barometric pressure

Option D: None of these

Correct Answer: None of these ✔

Option A: Partial pressure

Option B: Mole ratio

Option C: Mole fraction

Option D: None of these

Correct Answer: Mole ratio ✔

Option A: Kinematic viscosity

Option B: Dynamic viscosity

Option C: Surface tension

Option D: Pressure

Correct Answer: Kinematic viscosity ✔

Option A: Kc = Kp = Km

Option B: Kc = Kp/RT = Km . RT/P

Option C: Kc = Kp . RT = Km . RT/p

Option D: None of these

Correct Answer: Kc = Kp . RT = Km . RT/p ✔

Option A: More than the wet bulb

Option B: Less than the wet bulb

Option C: Equal to the wet bulb

Option D: Equal to the dry bulb

Correct Answer: More than the wet bulb ✔

Option A: Humidity

Option B: Velocity

Option C: Temperature

Option D: All A., B. & C.

Correct Answer: D. All A., B. & C. ✔

Option A: Increases

Option B: Decreases

Option C: Remain same

Option D: Either A. or B., depends on the system

Correct Answer: Decreases ✔

Option A: Separation of the constituents is the most effective

Option B: No separation will occur

Option C: Amount of solvent required will be minimum

Option D: Solvent flow rate should be very low

Correct Answer: No separation will occur ✔

Option A: Film

Option B: Penetration

Option C: Surface-renewal

Option D: None of these

Correct Answer: Film ✔

Option A: Treybal

Option B: Scheibel

Option C: Podbielniak

Option D: None of these

Correct Answer: Podbielniak ✔

Option A: Minimum

Option B: Maximum

Option C: Infinite

Option D: Zero

Correct Answer: Minimum ✔

Option A: 0.54

Option B: 1.04

Option C: 1.24

Option D: 1.94

Correct Answer: 1.24 ✔

Option A: Increases

Option B: Decreases

Option C: Remains unchanged

Option D: Decreases exponentially

Correct Answer: Increases ✔

Option A: D ∝ P0.5

Option B: D ∝ 1/P0.5

Option C: D ∝ 1/P

Option D: D ∝ 1/P1.5

Correct Answer: D ∝ 1/P ✔

Option A: Classification

Option B: Sedimentation

Option C: Clarification

Option D: Leaching

Correct Answer: Sedimentation ✔

Option A: Yes

Option B: Normally not; but is possible if infinite number of plates are put

Option C: Never

Option D: Yes; if the reflux ratio is maximum

Correct Answer: Never ✔

Option A: Decreased solute solubility

Option B: Large minimum liquid to gas (L/G) ratio

Option C: Large number of trays

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Dialysis

Option B: Electrodialysis

Option C: Diffusion

Option D: Ultra-filtration

Correct Answer: Ultra-filtration ✔

Option A: Wetted wall column

Option B: Gilliland’s

Option C: Winkelmann’s

Option D: Wike’s

Correct Answer: C. Winkelmann’s ✔

Option A: Cylinder

Option B: Rotary

Option C: Spray

Option D: Fluidised bed

Correct Answer: Cylinder ✔

Option A: Small sizes

Option B: Multi-component distillation

Option C: High pressure operation

Option D: Vacuum distillation

Correct Answer: Small sizes ✔

Option A: Pulsed column

Option B: Sieve plate

Option C: Mixer-settler

Option D: Bollman

Correct Answer: Pulsed column ✔

Option A: Uranium from its ore

Option B: Water from petrol

Option C: Ammonia from coke oven gas

Option D: Mustard oil from mustard seed

Correct Answer: Water from petrol ✔

Option A: Pure component

Option B: Binary mixture

Option C: Ternary mixture

Option D: Insoluble binary system

Correct Answer: Pure component ✔

Option A: Dry-bulb

Option B: Wet-bulb

Option C: Dew point

Option D: Adiabatic saturation

Correct Answer: Wet-bulb ✔

Option A: 1.5

Option B: -0.6

Option C: -1.5

Option D: 0.6

Correct Answer: 1.5 ✔

Option A: Dew point < wet bulb temperature

Option B: Wet bulb temperature < dry bulb temperature

Option C: Both A. and B.

Option D: Neither A. not B.

Correct Answer: C. Both A. and B. ✔

Option A: Liquid side

Option B: Gas side

Option C: Interfacial

Option D: Both liquid and gas side

Correct Answer: Gas side ✔

Option A: Optimum number of trays

Option B: Minimum reboiler size

Option C: Maximum condenser size

Option D: Minimum number of trays

Correct Answer: Maximum condenser size ✔

Option A: Separation of a binary mixture by distillation

Option B: Absorption of NH3 from air by water

Option C: All liquid-liquid diffusion systems

Option D: All liquid-solid diffusion systems

Correct Answer: Separation of a binary mixture by distillation ✔

Option A: Diffusion co-efficient

Option B: Mass transfer co-efficient

Option C: NTU

Option D: None of these

Correct Answer: Mass transfer co-efficient ✔

Option A: Spray

Option B: Packed

Option C: Bubble cap plate

Option D: Wetted wall

Correct Answer: Wetted wall ✔

Option A: At ground level

Option B: 2 metres above the ground

Option C: 5 metres above ground

Option D: 10 metres above ground

Correct Answer: At ground level ✔

Option A: Thermal decomposition of bottoms

Option B: Increased relative volatility

Option C: Erosion of the tower

Option D: Very efficient operation

Correct Answer: Thermal decomposition of bottoms ✔