A (g) 3 B (g) + 0.5 C (g) According to the above reaction, A is on a catalyst at 325C and 3.5 Bar pressure. is falling apart. B and C are from the catalyst surface into the gas phase, and A is towards the catalyst surface. properly diffused. 510^6 m from each other, located near the catalyst in the gas phase. The mole fractions of A at two points away from