Mass Transfer Mcqs for Chemical - Set 14

1)   In case of an absorber, the operating _______________?

a. Line always lies above the equilibrium curve
b. Line always lies below the equilibrium curve
c. Line can be either above or below the equilibrium curve
d. Velocity is more than the loading velocity
Answer  Explanation 

ANSWER: Line always lies above the equilibrium curve

Explanation:
No explanation is available for this question!


2)   Radioactive nuclear waste is treated in____________________?

a. Mixer-settler extractor
b. Rotating-disc contactor
c. Pulsed column extractor
d. Bollman extractor
Answer  Explanation 

ANSWER: Pulsed column extractor

Explanation:
No explanation is available for this question!


3)   Langmuir equation is associated with________________________?

a. Leaching
b. Adsorption
c. Steam distillation
d. Multi-component absorption
Answer  Explanation 

ANSWER: Adsorption

Explanation:
No explanation is available for this question!


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

a. Low vapour pressure
b. Low velocity
c. Low freezing point
d. None of these
Answer  Explanation 

ANSWER: None of these

Explanation:
No explanation is available for this question!


5)   Raoult’s law applies to the___________________?

a. All liquid solutions
b. Non-ideal solution only
c. Non-volatile solute
d. Solvents
Answer  Explanation 

ANSWER: Solvents

Explanation:
No explanation is available for this question!


6)   A packed tower compared to a plate tower for a particular mass transfer operation__________________?

a. Incurs smaller pressure drop
b. Allows installation of cooling coils
c. Is less costly when built in large sizes/diameters
d. Is more suitable, if suspended solids are present in fluid streams
Answer  Explanation 

ANSWER: Incurs smaller pressure drop

Explanation:
No explanation is available for this question!


7)   Stacked packing compared to dumped packing_________________?

a. Provides poorer contact between the fluids
b. Gives lower pressure drop
c. Both A. and B.
d. Gives higher pressure drop
Answer  Explanation 

ANSWER: Both A. and B.

Explanation:
No explanation is available for this question!


8)   _______________ developed the film theory ?

a. Higbie
b. Fick
c. Ergun
d. Levenspiel
Answer  Explanation 

ANSWER: Higbie

Explanation:
No explanation is available for this question!


9)   Schmidt number is given by ___________________?

a. μ/ρDAB
b. Re × Pe
c. Sh × Pe
d. Re/Pe
Answer  Explanation 

ANSWER: μ/ρDAB

Explanation:
No explanation is available for this question!


10)   Fenske equation determines the __________________?

a. Maximum number of ideal plates
b. Height of the distillation column
c. Minimum number of theoretical plates
d. Optimum reflux ratio
Answer  Explanation 

ANSWER: Minimum number of theoretical plates

Explanation:
No explanation is available for this question!


11)   Hydrogenation of oil is carried out in a/an _______________ in Vanaspati manufacturing plant?

a. Agitated vessel
b. Sieve tray column
c. Bubble cap column
d. Packed tower
Answer  Explanation 

ANSWER: Agitated vessel

Explanation:
No explanation is available for this question!


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

a. [xD/(RD + 1)], [RD/(RD + 1)]
b. [RD/(RD + 1)], [xD/(xD + 1)]
c. [xD/(RD + 1)], [(RD + 1)/RD]
d. None of these
Answer  Explanation 

ANSWER: [RD/(RD + 1)], [xD/(xD + 1)]

Explanation:
No explanation is available for this question!


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

a. Agitated vessels
b. Bubble cap tray towers
c. Perforated sieve tray towers
d. Spray towers
Answer  Explanation 

ANSWER: Spray towers

Explanation:
No explanation is available for this question!


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

a. Wetted wall
b. Packed
c. Plate
d. Spray
Answer  Explanation 

ANSWER: Plate

Explanation:
No explanation is available for this question!


15)   On addition of solute in the solvent, the ______________ of the solution decreases ?

a. Boiling point
b. Freezing point
c. Vapour pressure
d. Both B. and C.
Answer  Explanation 

ANSWER: Both B. and C.

Explanation:
No explanation is available for this question!


16)   When adsorption hysteresis is observed, the desorption equilibrium pressure is _________________ that obtained by adsorption?

a. Always lower than
b. Always higher than
c. Same as
d. Dependent on the system; can be either lower or higher than
Answer  Explanation 

ANSWER: Always lower than

Explanation:
No explanation is available for this question!


17)   Extraction of penicillin employs a ________________ extraction column?

a. Centrifugal
b. Packed
c. Plate
d. None of these
Answer  Explanation 

ANSWER: Centrifugal

Explanation:
No explanation is available for this question!


18)   Which of these columns incurs the lowest pressure drop ?

a. Packed column (with stacked packing)
b. Packed column (with dumped packing)
c. Bubble plate column
d. Pulse column
Answer  Explanation 

ANSWER: Packed column (with stacked packing)

Explanation:
No explanation is available for this question!


19)   ‘Absorption with chemical reaction’ is involved in the removal of__________________?

a. Carbon dioxide from gaseous stream using alkaline solution
b. Benzol from coke oven gas using solar oil/wash oil
c. Ammonia from coke oven gas using refrigerated water
d. Tar from coke oven gas in primary gas coolers using chilled water
Answer  Explanation 

ANSWER: Carbon dioxide from gaseous stream using alkaline solution

Explanation:
No explanation is available for this question!


20)   Which of the following mixtures does not form an azeotrope at atmospheric pressure ?

a. Water-alcohol
b. Methyl alcohol-acetone
c. Butyl acetate-water
d. None of these
Answer  Explanation 

ANSWER: None of these

Explanation:
No explanation is available for this question!


21)   McCabe-Thiele method of binary distillation does not assume that the__________________?

a. Sensible heat changes are negligible compared with latent heat changes
b. Molar latent heats of all components are equal
c. Heat of mixing is negligible
d. None of these
Answer  Explanation 

ANSWER: None of these

Explanation:
No explanation is available for this question!


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

a. Bubble-cap column
b. Sieve-plate column
c. Packed column (stacked)
d. Randomly packed column
Answer  Explanation 

ANSWER: Packed column (stacked)

Explanation:
No explanation is available for this question!


23)   Absorption factor method is used to calculate the number of ideal stages, when_______________________?

a. Operating line lies above the equilibrium line
b. Operating line lies below the equilibrium line
c. Both operating and equilibrium lines are parallel
d. Pressure drop in the column is very high
Answer  Explanation 

ANSWER: Both operating and equilibrium lines are parallel

Explanation:
No explanation is available for this question!


24)   Entrainer used in Azeotropic distillation should____________________?

a. Form a low boiling azeotrope with one of the constituents of the mixture
b. Form a new azeotrope of low relative volatility with one of the constituents of the mixture
c. Have high latent heat of vaporisation
d. Have high viscosity to provide high tray efficiency
Answer  Explanation 

ANSWER: Form a low boiling azeotrope with one of the constituents of the mixture

Explanation:
No explanation is available for this question!


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

a. 0
b. 1
c. 2
d. 3
Answer  Explanation 

ANSWER: 0

Explanation:
No explanation is available for this question!


26)   For the same process conditions, the reflux ratio of an unlagged distillation column___________________?

a. Decreases in winter
b. Increases in winter
c. Increases in summer
d. None of these
Answer  Explanation 

ANSWER: Increases in winter

Explanation:
No explanation is available for this question!


27)   Minimum possible diameter of a packed column is decided mainly by the________________________?

a. Flooding
b. Gas viscosity
c. Liquid density
d. Liquid hold up
Answer  Explanation 

ANSWER: Flooding

Explanation:
No explanation is available for this question!


28)   Ponchon-Savarit method analyses the fractional equipment based on___________________?

a. Enthalpy balance only
b. Material balance only
c. Both enthalpy and material balances
d. The assumption of constant molal-overflow
Answer  Explanation 

ANSWER: Both enthalpy and material balances

Explanation:
No explanation is available for this question!


29)   Dryer widely used in a textile industry is ______________ dryer?

a. Festoon
b. Cylinder
c. Conveyor
d. Tunnel
Answer  Explanation 

ANSWER: Conveyor

Explanation:
No explanation is available for this question!


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

a. Sieve plate column
b. Bubble cap column
c. Randomly packed column
d. Wetted wall column
Answer  Explanation 

ANSWER: Wetted wall column

Explanation:
No explanation is available for this question!


31)   In a binary system, separation is very efficient, when the relative volatility is_______________?

a. 1
b. > 1
c. < 1
d. 0.5
Answer  Explanation 

ANSWER: > 1

Explanation:
No explanation is available for this question!


32)   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____________________?

a. T1-Dew point temp; T2-Dry bulb temp; T3-Wet bulb temp
b. T1-Dew point temp; T2-Wet bulb temp; T3-Dry bulb temp
c. T1-Wet bulb temp; T2-Dry bulb temp; T3-Dew point temp
d. T1-Dry bulb temp; T2-Wet bulb temp; T3-Dew point temp
Answer  Explanation 

ANSWER: T1-Dry bulb temp; T2-Wet bulb temp; T3-Dew point temp

Explanation:
No explanation is available for this question!


33)   Channelling in a packed tower results from the_____________________?

a. High pressure drop
b. Maldistribution of liquid
c. Non-uniformity of packing
d. Both B. and C.
Answer  Explanation 

ANSWER: Both B. and C.

Explanation:
No explanation is available for this question!


34)   Which of the following adsorbent is used in the refining of sugar?

a. Bone charcoal
b. Wood charcoal
c. Silica gel
d. Activated clay
Answer  Explanation 

ANSWER: Bone charcoal

Explanation:
No explanation is available for this question!


35)   With increase in pressure, the relative volatility for a binary system__________________?

a. Increases
b. Decreases
c. Remains same
d. Either A. or B., depends on the system
Answer  Explanation 

ANSWER: Decreases

Explanation:
No explanation is available for this question!


36)   Pick out the correct statement?

a. Diffusivity decreases with increase in temperature
b. Diffusivity increases with increase in molecular weight
c. Diffusivity increases with the size of the individual molecule
d. None of these
Answer  Explanation 

ANSWER: None of these

Explanation:
No explanation is available for this question!


37)   Pick out the wrong statement?

a. Critical moisture content is not a property of the material itself
b. A sharp increase in pressure drop gives an indication of the flooding in a distillation column
c. Separation of components is not possible in liquid extraction, if selectivity is unity
d. Dehydration of ethyl alcohol is most economically done by molecular distillation at very high vacuum
Answer  Explanation 

ANSWER: Dehydration of ethyl alcohol is most economically done by molecular distillation at very high vacuum

Explanation:
No explanation is available for this question!


38)   Pick out the wrong statement?

a. The operating line always lies above the equilibrium solubility curve in case of a single component absorber
b. The operating line always lies below the equilibrium solubility curve in case of a single component stripper
c. The operating pressure in solvent extraction system should be below vapor pressures of all components
d. The solubility of a particular gas in ideal solution in any solvent is always the same
Answer  Explanation 

ANSWER: The operating pressure in solvent extraction system should be below vapor pressures of all components

Explanation:
No explanation is available for this question!


39)   Pick out the wrong statement ?

a. Cellulose acetate membranes are used in dialysis process
b. Elutriation process refers to when the soluble material is largely concentrated on the surface of an insoluble solid and is simply washed off by the s
c. ‘Cascade’ means a group of stages interconnected so that various streams flow from one to another
d. Zirconia probe is used for the humidity measurement
Answer  Explanation 

ANSWER: Zirconia probe is used for the humidity measurement

Explanation:
No explanation is available for this question!


40)   Pick out the wrong statement?

a. In the McCabe-Thiele diagram for binary distillation, vertical feed line represents saturated liquid feed and horizontal feed line represents saturate
b. In small columns, local efficiency is larger than Murphree efficiency; in large columns local efficiency is smaller than Murphree efficiency
c. For Laminar flow over a plate of length L, the local mass transfer co-efficient at a distance L from the leading edge is 1.5 × 10-2m/s. Then the aver
d. The concentration and hydrodynamic boundary layers over a flat plate are of equal thickness, if Schmidt number is equal to unity
Answer  Explanation 

ANSWER: For Laminar flow over a plate of length L, the local mass transfer co-efficient at a distance L from the leading edge is 1.5 × 10-2m/s. Then the aver

Explanation:
No explanation is available for this question!