solve it please

Determine the required tray diameter for air-ammonia system using pure water. The mixture contains 20% ammonia and 80% air. It is desired to remove 80% ammonia. The gas enters at the bottom of the column at a flow rate of 200 kmole/h at 298 K and 1 atm. The water is fed at the top of the column at flow rate of 200 kmole/h. The surface tension of liquid is 72 dynes/cm and tray spacing is 18 inches. The density of the liquid is 1000 kg/m'. A foaming factor is 0.8 with 85% approach to the flooding velocity is recommended. Molecular weight of ammonia = 17.031 and of air = 29, respectively