1.- A countercurrent absorption process is to be used to recover solute A from an inert gas. The concentration of A will be reduced from 28.5 mol% A to 5 mol% A on solute free basis by contact with a pure solvent. a) Find the minimum liquid-to-vapor ratio on the free base of solute. b) Determine the number of stages in equilibrium if the actual velocity of the liquid were 1.2 times the minimum value. c) The concentration of A in the solvent solution at the outlet.

The equilibrium relationship can be expressed by yA = 4.0 xA.