First order catalysis refers to a reaction mechanism where the rate of the reaction is directly proportional to the concentration of one reactant. In the context of catalysis, this usually means that the reaction's rate is dependent on the concentration of the catalyst or a single reactant. The mathematical representation of this is often given by the rate law: \[ \text{Rate} = k[A] \] where \( k \) is the rate constant and \( [A] \) is the concentration of the reactant.
