The rate law of a multistep reaction mechanism is derived by writing elementary-step rate expressions directly from stoichiometry, then eliminating any reactive intermediate using either the steady-state approximation (setting the intermediate's net rate of formation to zero) or, for a fast pre-equilibrium followed by a slow step, an equilibrium-constant expression for the fast step combined with the rate-determining-step approximation. This belongs to chemical kinetics, specifically mechanism analysis, and requires that the derived rate law be tested for consistency against an experimentally determined rate law, since only elementary steps (not overall reactions) have rate laws determinable from stoichiometry alone.
The rate law of a multistep reaction mechanism is derived by writing elementary-step rate expressions directly from stoichiometry, then eliminating any reactive intermediate using either the steady-s…