Question 3 (30 marks) An air-NH3 mixture containing 5% NH3 by volume is absorbed in water using a packed tower at 200°C and 1 atm pressure to recover 98% NH3. Gas flow rate is 1200kg/h.m². The equilibrium relationship is y = 1.154x, where x and y are expressed in mole fraction units. (a) Calculate the minimum mass flowrate of liquid flow rate [15 marks] (b) Determine NTU using 1.25 times the minimum liquid flow rate [10 marks] (c) Calculate the height of a packed column using Koa = 128 kg/h.m².atm (5 marks] Page 2 of 5