Species A diffuses into a cylindrical pore where it reacts at the cylindrical surface to produce B $($A $-->$B$)$ according to a zero order reaction r$$A$($mol$/$cm$2$s$)=$ k$1$ where k$1=1\mathrm{.}2$times $10-6$ mol$/$cm$2$s$.$ There is no reaction at the end of the pore and the end is impermeable to A$.$ The inside diameter of the pore is $0\mathrm{.}1$ cm and its length L $=1\mathrm{.}0$ cm$.$ You can assume CA$($z$)$ is a function of z where z is the distance along the pore with z $=0$ at the entrance to the pore. The diffusivity of A in the pore is DAB $=0\mathrm{.}06$ cm$2/$s and CA$($z $=0)=$ CA$0=2\mathrm{.}5$times $10-3$ mol$/$cm$3.$ The inside pore diameter is D$.$

a$)$ Determine the consumption rate of A within the pore in mol$/$s$.$

b$)$ Determine the molar flux of A at z $=0\mathrm{.}2$ cm in mol$/$s$$cm$2$