By means of a plate column, acetone is absorbed from its mixture with air in a non-volatile absorption oil. The entering gas contains 12 mole percent acetone, and the entering oil is acetone-free. Of the acetone in the air, 98 percent is to be absorbed, and the concentration of the liquor at the bottom of the tower is to contain 5 mole percent acetone. The equilibrium relationship is ye = 1.90 Xe. Plot the operating line and determine the minimum number of stages. Hint: Choose 100 moles of entering gas as a basis