## microscopic diffusion control (encounter control)

https://doi.org/10.1351/goldbook.M03912
The observable consequence of the limitation that the rate of a @M03989@ @C01033@ in a homogeneous medium cannot exceed the rate of @E02086@ of the reacting @M03986@. If (hypothetically) a @M03989@ reaction in a homogeneous medium occurred instantaneously when two reactant molecular entities made an @E02086@, the @R05156@ would be an @E02089@, determined solely by rates of @D01716@ of reactants. Such a hypothetical 'fully @D01716@ controlled rate' is also said to correspond to 'total microscopic @D01720@', and represents the asymptotic limit of the @R05156@ as the @O04322@ for the chemical conversion of the @E02090@ into product (or products) becomes large relative to the @O04322@ for separation (or @D01801@) of the @E02090@. 'Partial microscopic @D01720@' is said to operate in a homogeneous reaction when the rates of chemical conversion and of separation are comparable. (The degree of microscopic @D01720@ cannot usually be determined with any @P04799@.)