Mass Transfer MCQs Archives

181. Which of the following processes is not an example of adsorption applied to gaseous separations?

Recovery of valuable solvent vapors from dilute mixture with air and other gases

Dehumidification of air and gas

Removal of objectionable odour and impurities from industrial gases

Decolouration of yellow glycerene

✅ The correct answer is option D.

182. In distillation column design, the McCabe-Thiele procedure is inadequate and a Ponchan-Savarit procedure is needed, when

Saturated feed is not used

An azeotrope forms

The latent heat of vaporisation of the more and less volatile components are greatly different

A total condenser is used

✅ The correct answer is option D.

183. H₂S present in naphtha reformed gas is removed by absorbing with

Ethanolamine

K₂CO₃

HCl

Vacuum gas oil

✅ The correct answer is option A.

184. What is the reflux ratio at total reflux?

Zero

Infinity

Unity

Data insufficient

✅ The correct answer is option B.

185. Gaseous diffusivity at atmospheric pressure is of the order of __________ cm²/second.

1 to 5

5 to 10

> 10

✅ The correct answer is option A.

186. L/mG is the expression for

Absorption factor

Brinkman number

Slope of operating line in absorber

Slope of operating line in stripper

✅ The correct answer is option A.

187. The binary diffusivity in gases does not depend upon the

Pressure

Temperature

Nature of the components

None of these

✅ The correct answer is option D.

188. Penetration theory states that the mass transfer co-coefficient is equal to (where, De is diffusivity and ‘t’ is time)

(De.t)1/2

(De/t)1/2

(4De/πt)1/2

(4De/t)

✅ The correct answer is option C.

189. What is the degree of freedom of an absorption process in which only one component is transferred between phases?

✅ The correct answer is option A.

190. The drying time between fixed moisture contents within the ‘constant rate period’ is proportional to (assuming that drying occurs from all surfaces of the solid) (where, T = thickness of the solid )

√T

T1.5

✅ The correct answer is option B.