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1- Pure water is passed through a tube constructed of solid benzoic acid. The benzoic acid is slightly soluble in water (denote the solubility as C moles of acid/ cm3 solution). The inner walls of tube is dissolved very slowly. It is possible to calculate the rate of mass transfer weighting the tube before and after the exposure. I-Assuming a steady state material balance for the flow profile, show that the following O.D. equation represents the case mathematically. U0dxdC+Kc(D4)(CC)=0 Where, D denotes the inner tube diameter (taken as approximately invariant), U0 is liquid velocity, and Kc is mass transfer constant. II- Show that the solution of the ODE in (I) is : C=C+Aexp(U0D4Kcx) III- Water inlet is a pure water, show that the final solution for the case is : C=C[1exp(U0D4Kcx)]