Rates and Rate Equations

The rate of a reaction shows how fast reactants are converted into products. It depends on the concentrations of the reactants and the rate constant.

The rate of reaction is given by the rate equation: Rate = k[A]^m [B]^n

The constants m and n show the order of the reaction with respect to that species. This means that different species can have more of an effect on the rate of reaction than others. The values m and n can be 0, 1 or 2 - corresponding to zero order, first order or second order. The total order of reaction for this chemical reaction can be found as the sum of the separate orders: Total order = m + n

Rate constant

The rate constant for a reaction is constant when the reaction temperature is constant. The rate constant relates the concentrations of the species that affect the rate of a reaction to the overall rate of reaction.

The rate constant, k, can be calculated by rearranging the rate equation for that reaction. It has varying units depending on the number of species and their orders of reaction. This can be found by substituting the units into the rearranged equation and cancelling. k = Rate/[A]^m [B]^n