Schmidt number and Lewis number for pure air at atmospheric conditions are respectively__________________?
A. < 1 and ≈ 1
B. 1 and 0
C. > 1 and ≈ 1
D. 0 and ≈ 1
Month: February 2019
The falling rate period in the drying of a solid is characterised by__________________?
The falling rate period in the drying of a solid is characterised by__________________?
A. Increase in rate of drying
B. Increasing temperatures both on the surface and within the solid
C. Decreasing temperatures
D. None of these
Azeotropism for ethyl alcohol-water system disappears by_____________________?
Azeotropism for ethyl alcohol-water system disappears by_____________________?
A. Increasing temperature
B. Decreasing pressure
C. Increasing pressure
D. No means
In a liquid-liquid extraction, 10 kg of a solution containing 2 kg of solute C and 8 kg of solvent A is brought into contact with 10 kg of solvent B. Solvent A and B are completely immiscible in each other whereas solute C is soluble in both the solvents. The extraction process attains equilibrium. The equilibrium relationship between the two phases is Y* = 0.9X, where Y* is the kg of C/kg of B and X is kg of C/kg of A. Choose the correct answer?
In a liquid-liquid extraction, 10 kg of a solution containing 2 kg of solute C and 8 kg of solvent A is brought into contact with 10 kg of solvent B. Solvent A and B are completely immiscible in each other whereas solute C is soluble in both the solvents. The extraction process attains equilibrium. The equilibrium relationship between the two phases is Y* = 0.9X, where Y* is the kg of C/kg of B and X is kg of C/kg of A. Choose the correct answer?
A. The entire amount of C is transferred to solvent B
B. Less than 2 kg but more than 1 kg of C is transferred to solvent B
C. Less than 1 kg of C is transferred to B
D. No amount of C is transferred to B
Acetone is to be removed from air in an isothermal dilute absorber using pure water as solvent. The incoming air contains 5 mole% of acetone (yin = 0.05). The design equation to be used for obtaining the number of trays (N) of the absorber is, N+2 = 6 log (yin/yout).For 98% recovery of acetone, the number of trays required is/are ?
Acetone is to be removed from air in an isothermal dilute absorber using pure water as solvent. The incoming air contains 5 mole% of acetone (yin = 0.05). The design equation to be used for obtaining the number of trays (N) of the absorber is, N+2 = 6 log (yin/yout).For 98% recovery of acetone, the number of trays required is/are ?
A. 4
B. 8
C. 9
D. 10
Sand is dried in foundries in a ______________________drier?
Sand is dried in foundries in a ______________________drier?
A. Rotary
B. Fluidised bed
C. Vacuum
D. Spray
Binary distillation involves the mass transfer by ______________________ at the gas-liquid interface?
Binary distillation involves the mass transfer by ______________________ at the gas-liquid interface?
A. Unidirectional diffusion from liquid to gas phase
B. Unidirectional diffusion from gas to liquid phase
C. Either A. or B.
D. A counter diffusion at an almost equal molar rate
Which of the following adsorbent is used to decolourise yellow glycerine ?
Which of the following adsorbent is used to decolourise yellow glycerine ?
A. Silica gel
B. Alumina
C. Fuller’s earth
D. Activated carbon
Surface renewal model of mass transfer was enunciated by___________________?
Surface renewal model of mass transfer was enunciated by___________________?
A. Toor and Marcello
B. Fick
C. Danckwerts
D. Stefan
If Rm is the minimum reflux ratio, the optimum reflux ratio may be around _________________ Rm ?
If Rm is the minimum reflux ratio, the optimum reflux ratio may be around _________________ Rm ?
A. 1.2 to 1.5
B. 2.5 to 3
C. 3 to 4
D. 5