QUESTION II: (25 marks) (a) An ammonia air mixture containing 2% by volume ammonia is to be scrubbed with ) water at 20C in a tower packed with 1.27 cm Raschig rings. The water and gas rates are 1170 kg/(hr.m) each, based on empty tower cross-section. Determine the height of the tower required if 98% of ammonia in the entering gas is to be absorbed. The tower operates at 1 atm. The equilibrium relationship is given by the following equation: ye -0.746 where ye-mole fraction of ammonia in air