A first order reaction A → B occurs in an isothermal porous catalyst pellet of spherical shape. If the concentration of A at the centre of the pellet is much less than at the external surface, the process is limited by__________________?

Question

Accepted Answer

Diffusion within the pellet. When the center concentration is much lower than the surface concentration, it means A moves from the surface to the center. This drop in concentration inside indicates that diffusion within the pellet controls the rate.