The rate law (rate equation) is an experimentally determined expression that relates the reaction rate to the concentrations of the reactants, each raised to a power called its order. The proportionality constant in the expression is the rate constant. The rate law cannot be deduced from the balanced equation; it must be found by experiment.

速率定律(速率方程)是由实验确定的表达式,它将反应速率与各反应物的浓度相联系,每个浓度都取一个称为其级数的幂。该表达式中的比例常数即为速率常数。速率定律不能由配平方程式推得,必须通过实验求得。