Mass Transfer MCQs

Option A: 5

Option B: 30

Option C: 60

Option D: 100

Correct Answer: 30 ✔

Option A: > 4 :1

Option B: < 8 : 1

Option C: > 8:1

Option D: < 6:1

Correct Answer: > 8:1 ✔

Option A: Liquid extraction

Option B: Distillation

Option C: Evaporation

Option D: Absorption

Correct Answer: Liquid extraction ✔

Option A: Composition of vapors and that of liquid do not vary throughout the column

Option B: Reboiler load and condenser load are minimum

Option C: The top and bottom compositions are unchanged with and without total reflux

Option D: The top and bottom compositions correspond to the maximum enrichment available

Correct Answer: The top and bottom compositions correspond to the maximum enrichment available ✔

Option A: High maintenance cost

Option B: Non-uniform & low production rate

Option C: High labour cost & low heat economy

Option D: All ‘a’, ‘b’ & ‘c’

Correct Answer: High labour cost & low heat economy ✔

Option A: Solid dispersed in liquid

Option B: Solid dispersed in gas

Option C: Liquid dispersed in gas

Option D: Gas dispersed in liquid

Correct Answer: Solid dispersed in gas ✔

Option A: Free flowing

Option B: Dry

Option C: Sticky

Option D: Granular

Correct Answer: Sticky ✔

Option A: 7

Option B: 70

Option C: 0.7

Option D: 150

Correct Answer: 7 ✔

Option A: +ve

Option B: -ve

Option C: Zero

Option D: None of these

Correct Answer: +ve ✔

Option A: 0.4

Option B: 0.25

Option C: 0.2

Option D: 0.175

Correct Answer: 0.2 ✔

Option A: Bound

Option B: Unbound

Option C: Critical

Option D: None of these

Correct Answer: Bound ✔

Option A: Drum drier

Option B: Spray drier

Option C: Tunnel drier

Option D: Tray drier

Correct Answer: Tray drier ✔

Option A: Vapors and liquids are at their dew point and bubble point respectively

Option B: Driving force for the liquid flow is its specific weight

Option C: Driving force for the vapor flow is the pressure drop, as the pressure decreases gradually from

Option D: Highest temperature is encountered at the top of the column

Correct Answer: C. Driving force for the vapor flow is the pressure drop, as the pressure decreases gradually from
the bottom to the top of the column ✔

Option A: Directly proportional to ‘T1.5’

Option B: Inversely proportional to ‘P’

Option C: Dependent on the molecular volume & molecular weight of components

Option D: All A , B. & C.

Correct Answer: D. All A , B. & C. ✔

Option A: Reboiler is not used in open steam distillation

Option B: The separation of solutes of different molecular sizes in a liquid solution by use of a suitable

Option C: Freeze drying is used for the drying of fish

Option D: Fenske-Underwood equation is used for calculating theoretical number of plates in a

Correct Answer: D. Fenske-Underwood equation is used for calculating theoretical number of plates in a
distillation column at normal operating reflux condition ✔

Option A: Electrical resistance

Option B: Thermal conductivity

Option C: Strength

Option D: None of these

Correct Answer: Electrical resistance ✔

Option A: Diffusion

Option B: Heat transfer

Option C: Both A. and B.

Option D: Neither A. nor B.

Correct Answer: Heat transfer ✔

Option A: Toluene-benzene

Option B: Acetone-carbon disulphide

Option C: Water-isobutyl alcohol

Option D: None of these

Correct Answer: Acetone-carbon disulphide ✔

Option A: Temperature

Option B: Vapour pressure of either component

Option C: Total pressure

Option D: None of these

Correct Answer: Temperature ✔

Option A: Packed column

Option B: Sieve tray

Option C: Bubble cap

Option D: Any of these

Correct Answer: Packed column ✔

Option A: 0.50

Option B: 0.60

Option C: 1

Option D: 2

Correct Answer: 0.50 ✔

Option A: Individual mass transfer co-efficient (M.T.C.) in gaseous system

Option B: M.T.C. of individual components in a liquid-liquid system

Option C: M.T.C. of liquid in liquid-gas system

Option D: The overall M.T.C. of the system

Correct Answer: Individual mass transfer co-efficient (M.T.C.) in gaseous system ✔

Option A: Rapid absorption rates and good heat transfer characteristics

Option B: Improved flooding characteristics

Option C: Low pressure drop on pumping

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

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

Option A: Gas side mass transfer co-efficient should be increased

Option B: Liquid side mass transfer co-efficient should be increased

Option C: Liquid side mass transfer co-efficient should be decreased

Option D: Mass transfer co-efficient must be kept constant

Correct Answer: Liquid side mass transfer co-efficient should be increased ✔

Option A: Allowable liquid velocity

Option B: Allowable gas velocity

Option C: Allowable gas and liquid velocities

Option D: Feed composition

Correct Answer: Allowable gas and liquid velocities ✔

Option A: Selectivity index

Option B: Relative volatility

Option C: Absorption factor

Option D: Murphree efficiency

Correct Answer: Absorption factor ✔

Option A: Affected more by temperature than that for gases

Option B: Affected much less by temperature than that for gases

Option C: Not affected by the temperature

Option D: None of these

Correct Answer: Affected more by temperature than that for gases ✔

Option A: (1 – f)/f

Option B: – (f – 1)/f

Option C: -1/f

Option D: -f/(1 – f)

Correct Answer: -1/f ✔

Option A: Lewis number

Option B: Schmidt number

Option C: Prandtl number

Option D: Sherwood number

Correct Answer: Lewis number ✔

Option A: Tunnel

Option B: Heated cylinder

Option C: Conveyor

Option D: Festoon

Correct Answer: Heated cylinder ✔

Option A: Partial pressure of the vapour to the vapour pressure of the liquid at room temperature

Option B: Partial pressure of the vapour to the vapour pressure of the liquid at gas temperature

Option C: Actual humidity to saturation humidity

Option D: None of these

Correct Answer: Partial pressure of the vapour to the vapour pressure of the liquid at gas temperature ✔

Option A: That of normal condensation

Option B: Integral heat of adsorption

Option C: Zero

Option D: None of these

Correct Answer: That of normal condensation ✔

Option A: A solution of benzene, toluene and o-xylene

Option B: 35% solution of camphor in water

Option C: 35% solution of NH3 in water

Option D: A solution of polar organic compounds (not of homologue of a series)

Correct Answer: A solution of benzene, toluene and o-xylene ✔

Option A: Chemical properties

Option B: Physical properties

Option C: Degree of turbulence

Option D: Interfacial area

Correct Answer: Chemical properties ✔

Option A: Both liquids flow at fixed rate

Option B: Both liquids can have any desired flow rate

Option C: Only one of the liquids may be pumped at any desired rate

Option D: Liquid’s flow rate depends upon the temperature and pressure

Correct Answer: Only one of the liquids may be pumped at any desired rate ✔

Option A: Greater degree of separation with a fixed number of trays

Option B: Increased reboiler load

Option C: Increased reflux ratio

Option D: None of these

Correct Answer: Increased reflux ratio ✔

Option A: K ∝ D

Option B: K ∝√D

Option C: K ∝ D1.5

Option D: K ∝ D2

Correct Answer: K ∝ D ✔

Option A: Maintaining high critical humidity

Option B: Maintaining low critical humidity

Option C: Coating the product with inert material

Option D: Both A. and C.

Correct Answer: D. Both A. and C. ✔

Option A: Only one component

Option B: Two components

Option C: Any number of components

Option D: Only saturated liquid

Correct Answer: Any number of components ✔

Option A: Ammonia in water

Option B: Benzol present in coke oven gas by wash oil

Option C: SO2 in alkaline solution

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

Correct Answer: SO2 in alkaline solution ✔

Option A: Decreases rapidly

Option B: Increases rapidly

Option C: Remain constant

Option D: Is maximum

Correct Answer: Is maximum ✔

Option A: S2/S1

Option B: S1/S2

Option C: S1 – S2

Option D: S1 × S2

Correct Answer: S1/S2 ✔

Option A: Spray dryer

Option B: Spouted bed dryer

Option C: Tunnel dryer

Option D: Pan open to atmosphere

Correct Answer: Spray dryer ✔

Option A: 0.60

Option B: 0.24

Option C: 1

Option D: 0.72

Correct Answer: 1 ✔

Option A: Increase both ‘G’ and ‘S’

Option B: Decrease both ‘G’ and ‘S’

Option C: Increase ‘S’ and decrease ‘G’

Option D: Increase ‘G’ and decrease ‘S’

Correct Answer: C. Increase ‘S’ and decrease ‘G’ ✔

Option A: Range is 15°F

Option B: Approach is 10°F

Option C: Both A. & B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. & B. ✔

Option A: Pachuka tank

Option B: Agitated vessels

Option C: Centrifugal extractors

Option D: Packed towers

Correct Answer: Pachuka tank ✔

Option A: Temperature rises

Option B: Pressure rises

Option C: Temperature falls

Option D: Pressure falls

Correct Answer: Temperature rises ✔

Option A: Flow rate of inlet air

Option B: Relative humidity of outlet air

Option C: Humidity of inlet air

Option D: Temperature of the solid

Correct Answer: Temperature of the solid ✔

Option A: Increases

Option B: Decreases

Option C: Remains unchanged

Option D: May increase or decrease; depends on the type of adsorbate

Correct Answer: Decreases ✔

Option A: Higher dew point

Option B: Higher absolute (specific) humidity

Option C: Higher relative humidity

Option D: Higher wet bulb temperature

Correct Answer: Higher relative humidity ✔

Option A: 9.21

Option B: 4.605

Option C: 100

Option D: 0.001

Correct Answer: 4.605 ✔

Option A: Packed

Option B: Pulse

Option C: Bubble cap

Option D: Sieve plate

Correct Answer: Packed ✔

Option A: Across

Option B: Above

Option C: Both A. & B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. & B. ✔

Option A: Viscosity

Option B: Density

Option C: Solubility

Option D: Relative volatility

Correct Answer: Solubility ✔

Option A: Results from very low gas velocity

Option B: Is desirable from point efficiency consideration

Option C: Is characterised by the presence of foam throughout the space between trays

Option D: Reduces the overall pressure drop

Correct Answer: Is characterised by the presence of foam throughout the space between trays ✔

Option A: Raising the temperature

Option B: Lowering the total pressure

Option C: Both A. and B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. and B. ✔

Option A: Gas

Option B: Room

Option C: Wet bulb

Option D: None of these

Correct Answer: Gas ✔

Option A: Temperature rises

Option B: Pressure rises

Option C: Temperature falls

Option D: Pressure falls

Correct Answer: Temperature rises ✔

Option A: 1

Option B: > 1

Option C: < 1

Option D: 0

Correct Answer: 1 ✔

Option A: At < 100

Option B: At > 210.6

Option C: Between 100 and 210

Option D: None of these

Correct Answer: At < 100 ✔

Option A: Alumina

Option B: Silica

Option C: Synthetic zeolites crystals/metal alumino-silicates

Option D: None of these

Correct Answer: Synthetic zeolites crystals/metal alumino-silicates ✔

Option A: 1

Option B: 2

Option C: 3

Option D: 4

Correct Answer: 1 ✔

Option A: Nsh = 2

Option B: Nst = 2

Option C: Nsc = 2

Option D: None of these

Correct Answer: Nsh = 2 ✔

Option A: Straight

Option B: Parallel

Option C: Both A. & B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. & B. ✔

Option A: p = P

Option B: p >>P

Option C: p < P

Option D: p << P

Correct Answer: p = P ✔

Option A: Molal diffusivity

Option B: Volumetric co-efficient

Option C: Mass transfer co-efficient

Option D: None of these

Correct Answer: Mass transfer co-efficient ✔

Option A: Yes

Option B: No

Option C: Yes; but height of cooling tower will be prohibitively high

Option D: Yes; but the air flow rate should be excessively high

Correct Answer: No ✔

Option A: 0.25

Option B: 2.5

Option C: 1.25

Option D: 0.0025

Correct Answer: 0.25 ✔

Option A: Condenser and reboiler loads are the same in both the cases

Option B: Reboiler load is the same in both the cases but condenser load is higher in case (ii)

Option C: Condenser load is the same in both the cases but reboiler load is higher in case (ii)

Option D: Both condenser and reboiler loads are higher in case (ii) as compared to case (i)

Correct Answer: Both condenser and reboiler loads are higher in case (ii) as compared to case (i) ✔

Option A: Wetted wall

Option B: Sieve/perforated tray

Option C: Bubble cap

Option D: Packed

Correct Answer: Packed ✔

Option A: 2.09 × 10-4

Option B: 2.09 × 10-5

Option C: 2.09 × 10-9

Option D: 2.09 × 10-12

Correct Answer: 2.09 × 10-4 ✔

Option A: Recovery of tannis from the tree barks and woods

Option B: Leaching sodium nitrate from Chilean nitrate bearing rock

Option C: Both A. and B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. and B. ✔

Option A: Multiple effect evaporator

Option B: Mechanical draft cooling tower

Option C: Rotary dryer

Option D: Rotating disc contactor

Correct Answer: Mechanical draft cooling tower ✔

Option A: Cold water leaving the tower and the wet bulb temperature of the surrounding air

Option B: Hot water entering the tower and the wet bulb temperature of the surrounding air

Option C: Hot water entering and the cooled water leaving the cooling tower

Option D: None of these

Correct Answer: Cold water leaving the tower and the wet bulb temperature of the surrounding air ✔

Option A: II, III

Option B: II, IV

Option C: IV, III

Option D: IV, II

Correct Answer: II, III ✔

Option A: Inverse

Option B: Exponential

Option C: Linear

Option D: Logarithmic

Correct Answer: Linear ✔

Option A: Less than

Option B: More than

Option C: Same as

Option D: Very much less

Correct Answer: More than ✔

Option A: Low vapor pressure

Option B: Low viscosity

Option C: High gas solubility

Option D: None of these

Correct Answer: None of these ✔

Option A: Increase

Option B: Decrease

Option C: Remain same

Option D: Data insufficient, can’t be predicted

Correct Answer: Increase ✔

Option A: The mixture exhibits an azeotrope at 101.3 kPa

Option B: The composition of the mixture, in percent by volume is: o-xylene 30, p-xylene 60. and mxylene

Option C: The composition of the mixture in mole percent is: o-xylene 30, p-xylene 60 and m-xyoene 10

Option D: The mixture contain optical isomers

Correct Answer: The mixture exhibits an azeotrope at 101.3 kPa ✔

Option A: Area between operating line and 45° diagonal x-y diagram

Option B: Condenser and reboiler surfaces

Option C: Tower cross-section

Option D: None of these

Correct Answer: Area between operating line and 45° diagonal x-y diagram ✔

Option A: McCabe-Thiele method

Option B: Ponchan-Savarit method

Option C: Enthalpy concentration method

Option D: Plate absorption column

Correct Answer: McCabe-Thiele method ✔

Option A: Water-hydrochloric acid

Option B: Acetone-carbon disulphide

Option C: Water-ethyl alcohol

Option D: n-heptane-n-octane

Correct Answer: Water-hydrochloric acid ✔

Option A: In towers packed with stacked packing

Option B: In towers packed randomly with crushed solids

Option C: In dumped packing of regular units

Option D: At very high liquid flow rate

Correct Answer: In towers packed with stacked packing ✔

Option A: Liquid-liquid extraction

Option B: Leaching

Option C: Extractive distillation

Option D: Steam distillation

Correct Answer: ✔

Option A: Vapour pressure of component A to that of component B

Option B: Vapour pressure of component A to the total pressure

Option C: Vapour pressure of component A to the partial pressure of A

Option D: Partial pressure of component A to the total pressure

Correct Answer: Vapour pressure of component A to that of component B ✔

Option A: High pressure drop

Option B: Low pressure drop

Option C: Low velocity of the liquid

Option D: High temperature

Correct Answer: High pressure drop ✔

Option A: Ideal solutions

Option B: Real solutions

Option C: Mixture of water and alcohol

Option D: Non-ideal gases

Correct Answer: Ideal solutions ✔

Option A: Rotary

Option B: Vacuum

Option C: Tunnel

Option D: Tray

Correct Answer: Rotary ✔

Option A: Benzene-toluene

Option B: Ethyl alcohol-water

Option C: Hydrochloric acid-water

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

Correct Answer: Ethyl alcohol-water ✔

Option A: Gilliland

Option B: Toor and Marcello

Option C: Stefan

Option D: Fick

Correct Answer: Toor and Marcello ✔

Option A: Stanton

Option B: Sherwood

Option C: Peclet

Option D: None of these

Correct Answer: Peclet ✔

Option A: The overhead product is minimum

Option B: Both the operating lines coincide with diagonal

Option C: Both A. and B.

Option D: Neither A. nor B.

Correct Answer: The overhead product is minimum ✔

Option A: Increases

Option B: Decreases

Option C: Remain same

Option D: May increase or decrease; depends on system

Correct Answer: Decreases ✔

Option A: Decoction

Option B: Percolation

Option C: Elutriation or elution

Option D: None of these

Correct Answer: Elutriation or elution ✔

Option A: Distillation

Option B: Evaporation

Option C: Absorption

Option D: Liquid extraction

Correct Answer: Liquid extraction ✔

Option A: 1

Option B: > 1

Option C: < 1

Option D: ≤ 1

Correct Answer: 1 ✔

Option A: Litre

Option B: kg

Option C: gm

Option D: c.c

Correct Answer: Litre ✔

Option A: Liquid-solid

Option B: Gas-solid

Option C: Fluid-solid

Option D: Solid-solid

Correct Answer: Fluid-solid ✔