equilibrium constant

For a general chemical reactionαA + βB … σS + τT … the equilibrium constant can be defined by where {A} is the activity of the chemical species A etc (activity is a dimensionless quantity). It is conventional to put the activities of the products in the numerator and those of the reactants in the denominator. See Chemical equilibrium for a derivation of this expression.
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Noun
1. (chemistry) the ratio of concentrations when equilibrium is reached in a reversible reaction (when the rate of the forward reaction equals the rate of the reverse reaction)
(hypernym) constant
(hyponym) dissociation constant
(classification) chemistry, chemical science