Water containing 0.1-M benzoic acid flows at 0.1 cm/sec through a l-cm-diameter rigid tube of cellulose acetate, the walls of which are permeable to small electrolytes. These walls are 0.01 cm thick; solutes within the walls diffuse as through water. The tube is immersed in a large well-stirred water bath. Under these conditions, the flux of benzoic acid from the bulk to the walls can be described by the correlation in Problem 8.2. After 50 cm of tube, what fraction of a 0.1-M benzoic acid solution has been removed? Remember that there is more than one resistance to mass transfer in this system.