text: reaction kinetics: in determining the rate of reation, what is the "order of reaction"???   the power to which the concentration of the reactant is raised in the rate law.  first order reactions, the rate is proportional to the concentration of a single reactant raised to the first power. second order reactions, rate is proportional to the concentration of a single reactant squared or 2 different reactants each to the first power.  overall reaction orders will help understand how a reaction progresses.