Problem 4 Consider a system in which gas A diffuses through a stagnant film through the surface of a non porous catalyst particle where it reacts irreversibly according to nAR1B. Obtain the flux at the surface when the reaction is very fast and instantaneous. Notice that it the reaction is very fast A will be consumed instantly. And the surface BC will be that xA=0 at the surface r=R. and xA=xA0 at r=r