chemical engineering mass transfer MCQs – Page 7

Practise multiple-choice questions from chemical engineering mass transfer for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

chemical engineering mass transfer Mcqs

121. A pure drug is administered as a sphere and as a cube. The amount of drug is the same in the two tablets. Assuming that the shape and size do not influence the mass transfer, the ratio of rate of dissolution in water at t = 0 for the cubic to spherical tablet is___________________?
0

A. 1.24

B. 1.94

C. 1.04

D. 0.54

122. Dorr thickener is an equipment used for______________________?
0

A. Clarification

B. Leaching

C. Sedimentation

D. Classification

123. Dried finished product sampled from various parts of a ________________ dryer exhibits nonuniformity in the moisture content?
0

A. None of these

B. Tray

C. Rotary

D. Freeze

124. In distillation where q is defined as the moles of liquid flow in the stripping section per mole of feed introduced, for saturated liquid feed____________________?
0

A. q > 1

B. q = 1

C. q < 1

D. q = 0

125. Pick out the wrong statement ?
0

A. Co-current absorbers are usually used, when the gas to be dissolved in the liquid is a pure

B. stance

C. In case of gas absorption, HETP is equal to HTU, when both the operating line & the

D. ilibrium lines are parallel

E. Hatta number is important in case of gas absorption with chemical reaction

F. In actual practice, absorption is an endothermic process, while stripping is an exothermic

126. Coffee is prepared from coffee beans by leaching with____________________?
0

A. Hot water

B. Dilute hot caustic solution

C. Cold water

D. Naphtha

127. In case of unsaturated air_________________?
0

A. Dew point < wet bulb temperature

B. Wet bulb temperature < dry bulb temperature

C. Both A. and B.

D. Neither A. not B.

128. The Hatta number is important in_________________?
0

A. Gas absorption without chemical reaction

B. Binary distillation

C. Multi-component distillation

D. Gas absorption with chemical reaction

129. The process employing desorption of the absorbed solute by a solvent is called____________________?
0

A. Osmosis

B. Reverse osmosis

C. Elution

D. Sublimation

130. A 25 cm 25 cm 1 cm flat sheet weighing 1.2 kg initially was dried from both sides under constant drying rate conditions. It took 1500 seconds for the weight of the sheet to reduce to 1.05 kg. Another 1m 1m 1cm flat sheet of the same material is to be dried from one side only. Under the same constant drying rate conditions, the time required for drying (in seconds) from its initial weight of 19.2 kg to 17.6 kg is ____________________?
0

A. 2000

B. 2500

C. 1000

D. 1500

131. 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) ?
0

A. 1200

B. 500

C. 800

D. 900

132. In case of physical adsorption, the difference between heat of adsorption and heat of normal condensation is_________________?
0

A. Called integral heat of adsorption

B. Equal to the heat of formation of surface compound

C. Equal to the heat of wetting

D. Zero

133. Most important factor to be considered in the selection of packings for absorbers is the ______________ of packing?
0

A. Porosity

B. Durability

C. Size

D. Cost

134. Henrys law states that the ________________________?
0

A. Partial pressure of a component over a solution is proportional to the mole fraction in the

B. our

C. Partial pressure is equal to the product of the mole fraction and total pressure

D. uid</strong>

E. Vapour pressure is equal to the product of the mole fraction and total pressure

F. Partial pressure of a component over a solution is proportional to its mole fraction in the

135. The temperature of water cooled in cooling tower is always _________________ temperature of entering air?
0

A. Less than the wet bulb

B. More than the wet bulb

C. Equal to the wet bulb

D. Equal to the dry bulb

136. High pressure at the bottom of a distillation tower handling heat sensitive materials results in _____________________?
0

A. Thermal decomposition of bottoms

B. Erosion of the tower

C. Increased relative volatility

D. Very efficient operation

137. Use of packed towers for distillation is generally limited to the__________________?
0

A. Multi-component distillation

B. Vacuum distillation

C. High pressure operation

D. Small sizes

138. Pick out the wrong statement?
0

A. Mass transfer co-efficient does not account for gas-liquid diffusion

B. Contacting cold vapor-gas mixture with hot liquid exemplifies humidification process

C. Diffusion co-efficient and mass transfer co-efficient are not same in any mass transfer

D. Contacting cold liquid with warm vapor-gas mixture exemplifies dehumidification process

E. ration

139. Use of packed towers for distillation is generally limited to the____________________?
0

A. Multi-component distillation

B. Vacuum distillation

C. Small sizes

D. High pressure operation

140. Laboratory determination of the diffusivity of vapor is done by ______________ method?
0

A. Gillilands

B. Winkelmanns

C. Wikes

D. Wetted wall column

Previous Next

Showing 121 to 140 of 697 mcqs