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In chemical kinetics a reaction rate constant or reaction rate coefficient, ''k'', quantifies the rate of a chemical reaction.〔http://www.chem.arizona.edu/~salzmanr/480a/480ants/chemkine.html〕 For a reaction between reactants A and B to form product C : the reaction rate is often found to have the form: : Here ''k''(''T'') is the reaction rate constant that depends on temperature. () and () are the molar concentrations of substances A and B in moles per unit volume of solution, assuming the reaction is taking place throughout the volume of the solution. (For a reaction taking place at a boundary one would use instead moles of A or B per unit area). The exponents ''m'' and ''n'' are called partial orders of reaction and are ''not'' generally equal to the stoichiometric coefficients a and b. Instead they depend on the reaction mechanism and can be determined experimentally. ==Temperature dependence== The Arrhenius equation gives the quantitative basis of the relationship between the activation energy and the reaction rate at which a reaction proceeds. The rate constant is then given by : and the reaction rate by : where ''Ea'' is the activation energy, and ''R'' is the gas constant. Since at temperature ''T'' the molecules have energies according to a Boltzmann distribution, one can expect the proportion of collisions with energy greater than ''Ea'' to vary with ''e''−''Ea''/''RT''. ''A'' is the pre-exponential factor, or frequency factor (not to be confused here with the reactant A). 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Reaction rate constant」の詳細全文を読む スポンサード リンク
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