Top 550+ Solved Mass Transfer MCQ Questions Answer
Q. In case of binary distillation, increasing the reflux ratio above optimum does not result in the increase of
a. Area between operating line and 45° diagonal x-y diagram
b. Condenser and reboiler surfaces
c. Tower cross-section
d. None of these
Q. Advantage of continuous drying over batch drying is that the
a. Drying cost per unit weight of dried product is less
b. Product with more uniform moisture content is produced
c. Equipment size required is smaller
d. All 'a', 'b' & 'c'
Q. Which of the following assumes constant molal vaporisation and overflow?
a. McCabe-Thiele method
b. Ponchan-Savarit method
c. Enthalpy concentration method
d. Plate absorption column
Q. An air-water vapour mixture has a dry bulb temperature of 60°C and a dew point temperature of 40°C. The total pressure is 101.3 kPa and the vapour pressure of water at 40°C and 60°C are 7.30 kPa and 19.91 kPa respectively. The humidity of air sample expressed as kg of water vapour/kg of dry air is:
a. 0.048
b. 0.079
c. 0.122
d. 0.152
Q. Which of the following binary systems is an example of a maximum boiling azeotrope?
a. Water-hydrochloric acid
b. Acetone-carbon disulphide
c. Water-ethyl alcohol
d. n-heptane-n-octane
Q. For an absorber, both equilibrium and operating line will be straight for
a. Concentrated solution and non-isothermal operation
b. Dilute solution and non-isothermal operation
c. Dilute solution and isothermal operation
d. Concentrated solution and isothermal operation
Q. Channelling is most severe
a. In towers packed with stacked packing
b. In towers packed randomly with crushed solids
c. In dumped packing of regular units
d. At very high liquid flow rate
Q. Penetration model (theory) for mass transfer was enunciated by
a. Danckwerts
b. Toor and Marcello
c. Higbie
d. Kissinevskii
Q. Pick out the correct statement.
a. Bound moisture is removed during constant rate drying period
b. Free moisture is removed during falling rate drying period
c. The sum of free moisture and equilibrium moisture in a solid is called the critical moisture
d. The driving force for mass tr
Q. Extraction of coffee from its seed is done by
a. Liquid-liquid extraction
b. Leaching
c. Extractive distillation
d. Steam distillation
Q. Unit of molal diffusivity is
a. cm2/sec gm . mole
b. gm moles/cm2 . sec
c. gm moles/cm. sec
d. gm moles/cm2. sec
Q. 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
Q. In case of non-ideal gases and liquids, the molal diffusivity
a. Varies inversely as the pressure
b. Varies directly as the pressure
c. Is independent of pressure
d. Is equal to the volumetric diffusivity
Q. Flooding in a column results due to
a. High pressure drop
b. Low pressure drop
c. Low velocity of the liquid
d. High temperature