An equilibrium stage tower running at ambient conditions is to be used to remove so2 from an air mixture by absorption with pure water. the flow rate of the inlet gas mixture is 1.38 lbmol/min. the inlet mole fraction of so2 is 5.5x10^-4 and 90% removal is required. the equilibrium relationship is ye = 33xs. a) calculate the minimum flow rate of pure water in gal/min. b) determine the number of ideal stages that are needed if the water flow rate is 1.5 times the minimum by using the kremser equation and the mccabe-thiele graphical method.