please answer all a,b,c, and d

Q3) An absorber is run to remove ammonia from a gas. The ammonia will be removed using countercurrent operation of a packed bed column. The entering gas is composed of 75 mol% ammonia and 25 mol% air. The gas flowrate is 340 kmol/hr. The column operates at constant conditions of 323 K and 120 kPa. The required rate of ammonia recovery for this column is 85%. Pure liquid water enters the column at a rate of 280 kmol/hr. The tower is packed with 50 mm plastic Hiflow rings and will be designed for a maximum pressure drop of 70 Pa/m of packed height. (a) Estimate the loading and flooding gas velocities for these conditions. (b) Estimate the column diameter for these conditions. (c) Estimate the liquid holdup in the column. (d) Assume liquid diffusivity of 3.2 x 10 cm/s and a gas diffusivity of 0.092 cm /s, find the liquid and gas mass transfer coefficients, ke and ky