In
chemistry
Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound, compounds made of atoms, molecules and ions ...
, the effective molarity (denoted ''EM'')
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 (''Kinetic Effective Molarity'')
or the ratio between the
equilibrium constant of an
intramolecular reaction and the
equilibrium constant of the corresponding intermolecular reaction (''Thermodynamic Effective Molarity'').
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
A physical quantity is a physical property of a material or system that can be quantified by measurement. A physical quantity can be expressed as a ''value'', which is the algebraic multiplication of a ' Numerical value ' and a ' Unit '. For examp ...
.
See also
*
Cyclic compound
*
Intramolecular reaction
*
Macrocycle
*
Polymerization
References
{{Reflist
Physical organic chemistry