Past exam of the chemistry course of the year 3 of the natural sciences course of the University of Cambridge / 2022 / Paper 4 / 64 / d / i

For competing reactant and product species on shared equivalent sites, add each $b_j{C}_j$ term to the denominator:Rapid product desorption makes product coverages small, reducing competitive site blocking and simplifying the rate to reactant coverage alone. Without that assumption, product adsorption can inhibit conversion and make the apparent rate evolve as products accumulate.