Cooled
Humidified
Both A & B
Dehumidified
✅ The correct answer is option B.
Mass Transfer MCQs
52. Unsaturated air (with dry bulb and wet bulb temperatures being 45°C and 25°C respectively) is passed through a water spray chamber maintained at 23°C. The air will be cooled and
Humidified with wet bulb temperature decreasing
Humidified at constant wet bulb temperature
Dehumidified
None of these
✅ The correct answer is option A.
53. For water-ethanol system, the minimum reflux ratio
Is computed from the slope of the upper operating line that is tangent to the equilibrium curve
Is computed from the intercept of the operating line
Cannot be computed
Is the optimum reflux ratio
✅ The correct answer is option A.
54. In extraction, as the temperature increases, the area of hetrogeneity (area covered by binodal curve)
Decreases
Increases
Remains unchanged
None of these
✅ The correct answer is option A.
55. Absorption accompanied by heat evolution results in
Increased capacity of the absorber
Increase in equilibrium solubility
Decrease in equilibrium solubility
None of these
✅ The correct answer is option C.
56. The value of NA/(NA + NB), for steady state equimolal counter diffusion of two gases ‘A’ and ‘B’ is
1
∞
0.5
2
✅ The correct answer is option B.
57. Prandtl number for water at 20°C is about
7
70
0.7
150
✅ The correct answer is option A.
58. If the solubilities of different components (in a liquid-liquid extraction system) increase with rise in temperature, then the temperature above which they dissolve completely is known as the critical solution temperature (CST or consolute temperature). If solubilities increase with decrease in temperature, then CST is the temperature below which they dissolve completely. If a binary system has no critical solution temperature, it implies that
The system comprises of partially mis-cible liquids
The system comprises of miscible liquids
The system comprises of an azeotrope
On heating, a vapor phase will appear ; while on cooling, a solid phase will appear
✅ The correct answer is option D.
59. Design calculation for multiple component distillation is done by
Ponchon-Savarit method
Mccabe-Thiele method
Enthalpy concentration method
Tray to tray calculations
✅ The correct answer is option D.
60. Which of the following is an undesirable characteristic for the solvent used in gas absorption?
Low vapor pressure
Low viscosity
High gas solubility
None of these
✅ The correct answer is option D.