Effective molarity


In chemistry, the effective molarity is defined as the ratio between the first-order rate constant of an intramolecular reaction and the second-order rate constant of the corresponding intermolecular reaction or the ratio between the equilibrium constant of an intramolecular reaction and the equilibrium constant of the corresponding intermolecular reaction.
EM has the dimension of concentration. High EM values always indicate greater ease of intramolecular processes over the corresponding intermolecular ones. Effective molarities can be used to get a deeper understanding of the effects of intramolecularity on reaction courses. In last decades, the frequency of use of effective molarity in scientific literature has shown a marked decrease, because this formalism is being progressively replaced by more important physical quantities.