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In chemistry, the rate equation (also known as the rate law or empirical differential rate equation) is an empirical differential mathematical expression for the reaction rate of a given reaction in terms of concentrations of chemical species and constant parameters (normally rate coefficients and partial orders of reaction) only. [1]
In physical chemistry, the Arrhenius equation is a formula for the temperature dependence of reaction rates.The equation was proposed by Svante Arrhenius in 1889, based on the work of Dutch chemist Jacobus Henricus van 't Hoff who had noted in 1884 that the van 't Hoff equation for the temperature dependence of equilibrium constants suggests such a formula for the rates of both forward and ...
In chemical kinetics, an Arrhenius plot displays the logarithm of a reaction rate constant, ( (), ordinate axis) plotted against reciprocal of the temperature (/, abscissa). [1] Arrhenius plots are often used to analyze the effect of temperature on the rates of chemical reactions.
In chemical kinetics, the pre-exponential factor or A factor is the pre-exponential constant in the Arrhenius equation (equation shown below), an empirical relationship between temperature and rate coefficient. It is usually designated by A when determined from experiment, while Z is usually left for collision frequency. The pre-exponential ...
Another example is the unimolecular nucleophilic substitution (S N 1) reaction in organic chemistry, where it is the first, rate-determining step that is unimolecular. A specific case is the basic hydrolysis of tert-butyl bromide (t-C 4 H 9 Br) by aqueous sodium hydroxide. The mechanism has two steps (where R denotes the tert-butyl radical t-C ...
These reactions frequently have a pressure and temperature dependence region of transition between second and third order kinetics. [8] Catalytic reactions are often three-component, but in practice a complex of the starting materials is first formed and the rate-determining step is the reaction of this complex into products, not an ...
First-order logic, a formal logical system used in mathematics, philosophy, linguistics, and computer science First-order predicate , a predicate that takes only individual(s) constants or variables as argument(s)
Reaction coordinates are special order parameters that describe the entire pathway from reactants through transition states and on to products. Depending on the application, reaction coordinates may be defined by using chemically intuitive variables like bond lengths, or splitting probabilities (also called committors), or using the ...