2. Ninety-five percent of the acetone vapor in an 85 vol\% air stream is to be absorbed by countercurrent contact with pure water in a valve-tray column with an expected overall tray efficiency of 50%. The column will operate essentially at 20C and 101kPa pressure. Equilibrium data for acetone-water at these conditions are: Calculate a) The minimum value of L/V, the ratio of moles of water per mole of air b) The number of equilibrium stages required using a value of 25% over the minimum c) The concentration of acetone in the exit water