Elementary reaction
An elementary reaction is a
reaction intermediates have been detected or need to be postulated to describe the reaction on a molecular scale.[1] An apparently elementary reaction may be in fact a stepwise reaction
, i.e. a complicated sequence of chemical reactions, with reaction intermediates of variable lifetimes.
In a
isomerises
to form the products(s)
At constant temperature, the rate of such a reaction is proportional to the concentration of the species A
![{\displaystyle {\frac {d[{\mbox{A}}]}{dt}}=-k[{\mbox{A}}].}](https://wikimedia.org/api/rest_v1/media/math/render/svg/dd60e0eed0d75c439483d4df73e4dfe1cb25def2)
In a
, A and B, react together to form the product(s)
The rate of such a reaction, at constant temperature, is proportional to the product of the concentrations of the species A and B
![{\displaystyle {\frac {d[{\mbox{A}}]}{dt}}={\frac {d[{\mbox{B}}]}{dt}}=-k[{\mbox{A}}][{\mbox{B}}].}](https://wikimedia.org/api/rest_v1/media/math/render/svg/f53691c918b011c6bcf181176343ca7195d383c9)
The rate expression for an elementary bimolecular reaction is sometimes referred to as the law of mass action as it was first proposed by Guldberg and Waage in 1864. An example of this type of reaction is a cycloaddition reaction. This rate expression can be derived from first principles by using
ideal gases. For the case of dilute fluids equivalent results have been obtained from simple probabilistic arguments.[2]
According to collision theory the probability of three chemical species reacting simultaneously with each other in a
Michaelis-Menten
approximations.
Notes
- PMID 19894929.
- ^ "Bimolecular routes to cubic autocatalysis - American Chemical Society - PDF Free Download". datapdf.com. Retrieved 2023-09-18.
- ISSN 0009-2509.