C 2AB All T Bulk Gas Zt PAD Y S T The above sketch shows the region very close to a non-porous flat catalyst surface where the reaction 2A B takes place. The species, "A and B move between the bulk gas (at the edge of the film) and the catalyst surface by means of molecular transport. Assuming that the molar flux of 'A' is known (from reaction rate measurements), solve for the steady-state mole fraction of A at the catalyst surface in terms of C, DAR. XARNA and of, where X is the mole fraction of A at the edge of the film