: a number that relates the rate of a chemical reaction with the concentrations of the reacting substances : the sum of all the exponents of the terms expressing concentrations of the molecules or atoms determining the rate of the reaction — compare first-order reaction , second-order reaction , third-order reaction , zero-order reaction ; molecularity
ORDER OF A REACTION
Meaning of ORDER OF A REACTION in English
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012