Chemical Engineering Mcqs

Which of the following gas-liquid contacting devices incurs the least pressure drop for a particular duty ?

(A) Grid tray tower
(B) Perforated tray tower
(C) Wetted wall tower
(D) Bubble cap tower

Submitted By :Ali Uppal

Compound A is extracted from a solution of A + B into a pure solvent S. A Co-current unit is used for the liquid-liquid extraction. The inlet rate of the solution containing A is 200 moles of B/hr.m2 and the solvent flow, rate is 400 moles of S/m2. hr. The equilibrium data is represented by Y = 3X2 , where Y is in moles of a A/moles of B and X is in moles A/moles of S. The maximum percentage extraction achieved in the unit is_________________________?

(A) 25%
(B) 50%
(C) 70%
(D) 90%

Submitted By :Ali Uppal

According to the film theory of mass transfer, the mass transfer co-efficient is proportional to (where, D = molecular diffusivity) ?

(A) D
(B) D2
(C) D0.5
(D) 1/D

Submitted By :Ali Uppal

For a distillation column operating at minimum reflux, the_______________________?

(A) Concentration of liquid and vapour leaving a plate will be same
(B) Reflux ratio will be maximum
(C) Number of plates required will be maximum
(D) None of these

Submitted By :Ali Uppal

_______________ diffusion is used for separating the isotopes of methane ?

(A) Thermal
(B) Pressure
(C) Concentration
(D) Force

Submitted By :Ali Uppal

For a fixed number of ideal stages in a distillation column, as the reflux ratio is increased, the difference in composition between the top and bottom product streams__________________?

(A) Increases
(B) Decreases
(C) Remain unaffected
(D) Passes through a maximum

Submitted By :Ali Uppal

The relative saturation of a partially saturated mixture of vapour and gas can be increased by ________________ of the mixture?

(A) Reducing the total pressure
(B) Increasing the total pressure
(C) Reducing the temperature
(D) Both

Submitted By :Ali Uppal

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

(A) -ve
(B) +ve
(C) 1
(D) -1

Submitted By :Ali Uppal

The McCabe ΔL law states that the____________________?

(A) Molar heats of vaporisation of components are nearly equal
(B) Linear crystal growth rate depends on the degree of super-saturation
(C) Linear crystal growth rate does not depend on the crystal size
(D) Linear crystal growth rate depends on the crystal size

Submitted By :Ali Uppal

Absorption accompanied by heat evolution results in____________________?

(A) Increased capacity of the absorber
(B) Increase in equilibrium solubility
(C) Decrease in equilibrium solubility
(D) None of these

Submitted By :Ali Uppal

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