2. A wetted-wall column (d=40 mm, L=1 m) is used for SO2-air-water system to determine average mass transfer coefficient (kx) at 1 atm and 30 C. The velocity of the gas entering the column is 0.2 m/s with a concentration of 2% SO2. The concentration of SO2 in the exit gas stream is 0.2%. Pure water enters the column. The concentration of SO2 in the exit water xAL=0.00012. The interfacial concentration of the liquid phase side is constant throughout the column