Ammonia, NH 3 , in air is being absorbed into water within the enclosed tank shown in the figure below. The liquid and gas phases are both well mixed, and mass transfer occurs only at the exposed...

Ammonia, NH₃, in air is being absorbed into water within the enclosed tank shown in the figure below. The liquid and gas phases are both well mixed, and mass transfer occurs only at the exposed gas–liquid interface. The diameter of the cylindrical tank is 4 m, total liquid volume inside the tank is

constant. The bulk gas pressure of ammonia is maintained at 0.02 atm, and the total gas pressure is constant at 1.0 atm. The system is isothermal at 20C. The inlet volumetric flow rate of water is 200 L/h and enters NH₃
free. You may assume that Henry’s law, p_Ai
 Hc_Ai
describes the equilibrium distribution of NH₃
between the gas and the liquid phases where H
 0.02 atm/(kg mol/m³). The film mass-transfer coefficients are k_G
 1:25 kg mol/m²
h atm and k_L
 0:05 kg mol/m²
h (kg mol/m³).

a. Determine the overall mass transfer coefficient, K_G.

b. Determine the partial pressure of NH3 at the gas–liquid interface, p_Ai.

c. Determine W_A
the total molar rate of ammonia transfer.

d. Develop a material balance for NH₃; then determine c_Ai
the concentration of NH₃
in the outlet liquid stream.