law of mass action

In chemistry, Law of Mass Action has two aspects: 1) the equilibrium aspect, concerning the composition of a reaction mixture at equilibrium and 2) the kinetic aspect concerning the rate equations for elementary reactions. Both aspects stem from the research by Guldberg and Waage (1864-1879) in which equilibrium constants were derived by using kinetic data and the rate equation which they had proposed. Guldberg and Waage also recognised that chemical equilibrium is a dynamic process in which rates of reaction for the forward and backward reactions must be equal.
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Noun
1. (chemistry) the law that states the following principle: the rate of a chemical reaction is directly proportional to the molecular concentrations of the reacting substances
(hypernym) law, law of nature
(classification) chemistry, chemical science