In a wetted-wall tower, an air-H2S mixture is flowing by a film of water which is flowing as a thin film down a vertical plate. The H2S is being absorbed from the air to the water at a total pressure of 1.50 atm abs and 30oC. The value of kc of 9.567 10-4 m/s has been predicted for the gas-phase mass-transfer coefficient. At a given point the mole fraction of H2S in the liquid at the liquid-gas interface is 2.0 10-5 and pA of H2S in the gas is 0.05 atm. The Henry s law equilibrium relation is pA(atm) = 609xA (mole fraction in liquid). Calculate the rate of absorption of H2S.

• A. 1.480 10^-3 kmol/m².s
• B. 1.486 10^-3 kmol/m².s
• C. 1.485 10^-3 kmol/m².s
• D. 1.487 10^-3 kmol/m².s