Please do both questions

1. a) In an experimental study of the absorption of ammonia by water in a wetted-wall column, the value of K was found to be 2.75 x 10*kmol/ms-kPa. At one point in the column, the composition of the gas and liquid phases were 8.0 and 0.115 mol % NH, respectively. The temperature was 300 K and the total pressure was 1 atm. Eighty five percent of the total resistance to mass transfer was found to be in the gas phase. At 300 K, ammonia-water solutions follow Henry's law up to 5 mol% ammonia in the liquid, with m = 1.6 when the total pressure is 1 atm. Calculate the individual film coefficients and interfacial concentrations (10 Marks) b) An old-fashioned glass apothecary jar contains a patent medicine. The neck is closed with a rubber stopper that is 20 mm tall, with a diameter of 10 mm at the bottom end, widening to 20 mm at the top end. The molar concentration of medicine vapor in the stopper is 2 10 kmol/m' at the bottom surface and is negligible at the top surface. If the mass diffusivity of medicine vapor in the rubber is 0.2 x 10-9 m2/s. Find the rate at which vapor exists through the stopper. State any assumptions. (10 Marks)