Explore topic-wise MCQs in Chemical Engineering.

This section includes 590 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.

1.

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

A. Packed towers
B. Plate towers
C. Spray towers
D. Wetted wall columns
Answer» E.
2.

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

A. Increases
B. Decreases
C. Remain same
D. May increase or decrease; depends on individual design
Answer» B. Decreases
3.

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

A. Increases
B. Remains unchanged
C. Decreases
D. Decreases linearly
Answer» B. Remains unchanged
4.

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» C. Remains same
5.

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» C. Remains same
6.

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

A. Increases
B. Decreases
C. Decreases linearly
D. Remain unaffected
Answer» C. Decreases linearly
7.

With increase in temperature, the leaching rate increases due to__________________?

A. Decreased liquid viscosity
B. Increased diffusivity
C. Both A. and B.
D. Neither A. nor B.
Answer» D. Neither A. nor B.
8.

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

A. Increased diffusivity
B. Decreased viscosity of liquid
C. Both A. and B.
D. Neither A. nor B.
Answer» D. Neither A. nor B.
9.

With increase in temperature, the mutual solubility of two liquids_________________?

A. Increases
B. Decreases
C. Remains unchanged
D. Decreases exponentially
Answer» B. Decreases
10.

With increase in temperature, the mutual solubility of two liquids___________________?

A. Increases
B. Decreases
C. Remains unchanged
D. Decreases exponentially
Answer» B. Decreases
11.

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

A. Increases
B. Decreases
C. Remain unaffected
D. Increases Linearly
Answer» B. Decreases
12.

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

A. Diffusivity of solute increases
B. Viscosity of solvent decreases
C. Thermal conductivity of solute increases
D. None of these
Answer» B. Viscosity of solvent decreases
13.

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

A. Increases
B. Decreases
C. Remain same
D. Either A. or B., depends on the system
Answer» C. Remain same
14.

With increase in the concentration of the adsorbate, the integral heat of adsorption____________________?

A. Increases
B. Decreases
C. Remains unchanged
D. May increase or decrease; depends on the type of adsorbate
Answer» C. Remains unchanged
15.

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___________________?

A. Decreases
B. Remains unchanged
C. Increases
D. Decreases exponentially
Answer» D. Decreases exponentially
16.

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 ?

A. Increases
B. Decreases
C. Remain same
D. Increases linearly
Answer» B. Decreases
17.

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

A. Increases
B. Decreases
C. Remain same
D. May increase or decrease; depends on system
Answer» C. Remain same
18.

With the lowering of equilibrium pressure, at a given temperature, the amount of adsorbate on the adsorbent ?

A. Increases
B. Decreases
C. Remain same
D. Either A. or B., depends on the system
Answer» C. Remain same
19.

With the lowering of equilibrium pressure, at a given temperature, the amount of adsorbate on the adsorbent______________________?

A. Increases
B. Decreases
C. Remain same
D. Either A. or B., depends on the system
Answer» C. Remain same
20.

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

A. A solution of benzene, toluene and o-xylene
B. 35% solution of camphor in water
C. 35% solution of NH3 in water
D. A solution of polar organic compounds (not of homologue of a series)
Answer» B. 35% solution of camphor in water
21.

Which of the following quantities need not be fixed before starting the design of a cocurrent absorber ?

A. Heat gain or loss
B. Flow rate of entering liquid
C. Flow rate of gas
D. None of these
Answer» C. Flow rate of gas
22.

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

A. Packed tower
B. Bubble-cap plate column
C. Sieve-plate column
D. Wetted wall column
Answer» B. Bubble-cap plate column
23.

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 ?

A. Humidification only
B. Heating only
C. Both heating and humidification
D. Evaporative cooling
Answer» D. Evaporative cooling
24.

Which of the following parameters remains constant during chemical dehumidification ?

A. Dry bulb temperature
B. Partial pressure of vapour
C. Wet bulb temperature
D. None of these
Answer» B. Partial pressure of vapour
25.

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» E.
26.

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

A. Moles transferred/ [(time) (area) (mole fraction)]
B. Moles transferred/ [(time) (area) (mass A/mass B)]
C. Moles transferred/ [(time) (area) (pressure)]
D. None of these
Answer» E.
27.

Which of the following is not a batch drier ?

A. Truck drier
B. Agitated pan drier
C. Fluidised bed drier
D. Vacuum shelf drier
Answer» D. Vacuum shelf drier
28.

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

A. Partial condenser
B. Total condenser
C. Reboiler
D. Both B. and C
Answer» E.
29.

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

A. Multiple effect evaporator
B. Mechanical draft cooling tower
C. Rotary dryer
D. Rotating disc contactor
Answer» C. Rotary dryer
30.

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 ?

A. Dew point
B. Humidity ratio
C. Wet bulb temperature
D. None of these
Answer» D. None of these
31.

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» B. Wood charcoal
32.

Which is the controlling factor for a drum drier ?

A. Diffusion
B. Heat transfer
C. Both A. and B.
D. Neither A. nor B.
Answer» C. Both A. and B.
33.

When the ____________________ the relative humidity of air decreases, despite an increase in the absolute humidity?

A. Temperature rises
B. Pressure rises
C. Pressure rises
D. Pressure falls
Answer» B. Pressure rises
34.

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

A. Natural
B. Forced
C. Induced
D. None of these
Answer» B. Forced
35.

When the solvent dissolves very little of solute, then__________________________?

A. Solvent of low latent heat of vaporisation should be used
B. Solvent of low freezing point should be used
C. Large quantity of solvent is required to extract the solute
D. Very small quantity of solvent is required
Answer» D. Very small quantity of solvent is required
36.

When the psychometric ratio is ______________ then the adiabatic saturation temperature and wet bulb temperature becomes equal?

A. 1
B. < 1
C. > 1
D.
Answer» B. < 1
37.

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?

A. Continuous
B. Steam
C. Azeotropic
D. None of these
Answer» C. Azeotropic
38.

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

A. Murphree efficiency > point efficiency
B. Murphree efficiency < point efficiency
C. Murphree efficiency = point efficiency
D. Murphree efficiency ≠ point efficiency
Answer» D. Murphree efficiency ≠ point efficiency
39.

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________________________?

A. Vapour pressure of component A to that of component B
B. Vapour pressure of component A to the total pressure
C. Vapour pressure of component A to the partial pressure of A
D. Partial pressure of component A to the total pressure
Answer» B. Vapour pressure of component A to the total pressure
40.

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

A. Mixture of two gases
B. Pure gas
C. Ideal gas
D. Sparingly soluble gas
Answer» C. Ideal gas
41.

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

A. Zero
B. Unity
C. Infinity
D. None of these
Answer» D. None of these
42.

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

A. -ve
B. +ve
C. 1
D. -1
Answer» B. +ve
43.

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

A. The partial pressure of water vapour increases
B. The specific humidity decreases
C. The relative humidity increases
D. The relative humidity decreases
Answer» E.
44.

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» B. Always higher than
45.

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 ?

A. As the acetone concentration increases, the solubility curves approach each other
B. Both the phases become identical at a particular common point on both the solubility curves called the plait point
C. The distribution curve which is a plot between x (acetone concentration in one phase) and y (acetone concentration in other phase) is analogous to x-y
D. All A., B. and C.
Answer» E.
46.

Wetted wall tower experiment determines the__________________?

A. Molal diffusivity
B. Volumetric co-efficient
C. Mass transfer co-efficient
D. None of these
Answer» D. None of these
47.

Wet bulb and dry bulb temperatures becomes identical at _______________ percent saturation curve?

A. 100
B. 50
C. 78
D. None of these
Answer» B. 50
48.

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

A. Less
B. More
C. Same
D. Unpredictable
Answer» B. More
49.

Weeping in a distillation column_____________________?

A. Increases tray efficiency
B. Provides large interfacial surface for mass transfer
C. Results due to very high gas velocity
D. Results due to very low gas velocity
Answer» E.
50.

Water-ethyl alcohol solution can be concentrated (in respect of alcohol concentration) by ________________ distillation?

A. Atmospheric
B. Vacuum
C. High pressure
D. None of these
Answer» C. High pressure