Rate equation
In chemistry, the rate equation (also known as the rate law or empirical differential rate equation) is an empirical differential mathematical expression for the reaction rate of a given reaction in terms of concentrations of chemical species and constant parameters (normally rate coefficients and partial orders of reaction) only. For many reactions, the initial rate is given by a power law such as v 0 = k [ A ] x [ B ] y {\displaystyle v_{0}\;=\;k[\mathrm {A} ]^{x}[\mathrm {B} ]^{y}} where [ A ] {\displaystyle [\mathrm {A} ]} and [ B ] {\displaystyle [\mathrm {B} ]} are the molar concentrations of the species A {\displaystyle \mathrm {A} } and B , {\displaystyle \mathrm {B} ,} usually in moles per liter (molarity, M {\displaystyle M} ).