Explain with a neat sketch and label the concentration profile of the solute A on the two sides of the interface in a dilute solution of the two-film theory. Section B (Answer any TWO Full Questions) Q2(a) Air at 101.3 kPa is blown across the bulb of a mercury thermometer. The bulb is covered with a wick. The wick is immersed in an organic liquid (MW = 58). The reading of the thermometer is 280.8 K. At this temperature the vapour pressure of the liquid is 5 kPa. Find the air temperature given that the psychrometric ratio is 2 kJ/kg K and the latent heat of vaporization of the liquid is 360 kJ/kg. Assume that the air which is blown is free from the organic vapour. (b) State with reasons whether overall mass transfer coefficients, determined at a given solute concentration, can be used at other solute concentrations when the equilibrium relation is not linear. [Total 20 Marks] Q3(a) Ammonia-air mixture containing 4% ammonia by mole is admitted to a counter current absorber at a rate of 50 m/h at 293 K and 101.3 kPa in order to reduce the ammonia content to 1% (mole). If pure water at a rate of 40 kg/h is used as a solvent, determine () actual and (minimum. Equilibrium data for absorption of ammonia in water at 293 K are given in the table Q2(a) X (kmol NH/ kmol HO) Y (kmol NHJ kmol air) 0.02 0.013 0.025 0.01 0.03 0.037 - [Total 10 Marks] 0.04 0.047 0.05 0.057 0.06 0.068 0..07 Q4(a) It is desired to absorb 95% of acetone by water from a mixture of acetone and nitrogen containing 1.5% of the component in a counter current tray tower. Total gas input is 30 kmole/hr and water enters the tower at a rate of 90 kmole/hr. The tower operates at 27C and 101.3 kPa. The equilibrium relation is Y=2.53X. Determine the number of ideal stages necessary for the separation using graphical method. (b) Illustrate and explain the significance of the operating line in the absorber and stripper. 0.078 (b) Provide an explanation on what ways the packed height depends on the cooling range and the approach? [15] [5]