Q3. A mixture of ammonia and air is scrubbed in a plate column with fresh water. If the ammonia concentration is reduced from 5 per cent to 0.01 per cent, and the water and air rates are 0.65 and 0.40 kg/m's, respectively, how many theoretical plates are required? The equilibrium relationship may be written as Y = X, where X is the mole ratio in the liquid phase