[H2 Chemistry] - Prettyinsolitude's Kinetics qns

UltimaOnline SG

Prettyinsolitude asked :

Hello! Could I ask if catalysts are considered reactants? Such as in rare determining steps? Can it be included in rate equations? Cause the defn is given that it only includes reactants? Cause I’m quite confused cause some of my examples in the notes includes catalysts in rate equations while some do not.

Catalysts are not reactants, but because they affect the rate of reaction, they must be included in the rate equation.

UltimaOnline SG

A catalyst is indeed a reactant of a sort, but it is not converted to a product. Instead it is temporarily used up (in the rate determining step), but subsequently regenerated. It's role is to speed up the reaction by providing an alternative mechanism pathway which requires a lower activation energy.