For a reaction mechanism consisting of a fast equilibrium reaction, a slow forward reaction, and a fast forward reaction, which of the following cannot appear in the overall rate law for the reaction?
A. Concentration of reactants
B. Rate constant of the equilibrium
C. Concentration of intermediates
D. Rate constant of the slow forward reaction
C
Since mechanisms are merely tools that help explain how certain reactions progress, the final rate law must contain only substances that are in the overall reaction. Intermediates, by definition, do not appear in the overall reaction.
