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  2. Arrhenius plot - Wikipedia

    en.wikipedia.org/wiki/Arrhenius_plot

    Arrhenius plot. 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. For a single rate-limited thermally activated ...

  3. Activation energy - Wikipedia

    en.wikipedia.org/wiki/Activation_energy

    In the Arrhenius model of reaction rates, activation energy is the minimum amount of energy that must be available to reactants for a chemical reaction to occur. [1] The activation energy (Ea) of a reaction is measured in kilojoules per mole (kJ/mol) or kilocalories per mole (kcal/mol). [2] Activation energy can be thought of as the magnitude ...

  4. Arrhenius equation - Wikipedia

    en.wikipedia.org/wiki/Arrhenius_equation

    Formula for temperature dependence of rates of chemical reactions. 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 ...

  5. Eyring equation - Wikipedia

    en.wikipedia.org/wiki/Eyring_equation

    The Eyring equation (occasionally also known as Eyring–Polanyi equation) is an equation used in chemical kinetics to describe changes in the rate of a chemical reaction against temperature. It was developed almost simultaneously in 1935 by Henry Eyring, Meredith Gwynne Evans and Michael Polanyi. The equation follows from the transition state ...

  6. Energy profile (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Energy_profile_(chemistry)

    Figure 13 shows a common way to illustrate the effect of an enzyme on a given biochemical reaction. [11] Figure 12: An energy profile, showing the products (Y), reactants (X), activation energy (E a) for the endothermic and exothermic reaction, and the enthalpy (ΔH). The profile for same reaction but with a catalyst is also shown.

  7. Transition state theory - Wikipedia

    en.wikipedia.org/wiki/Transition_state_theory

    The free energy of activation, ΔG ‡, is defined in transition state theory to be the energy such that ‡ = ⁡ ‡ ′ holds. The parameters ΔH ‡ and ΔS ‡ can then be inferred by determining ΔG ‡ = ΔH ‡ – TΔS ‡ at different temperatures.

  8. Activated complex - Wikipedia

    en.wikipedia.org/wiki/Activated_complex

    In chemistry, an activated complex represents a collection of intermediate structures in a chemical reaction when bonds are breaking and forming. The activated complex is an arrangement of atoms in an arbitrary region near the saddle point of a potential energy surface. [1] The region represents not one defined state, but a range of unstable ...

  9. Activity coefficient - Wikipedia

    en.wikipedia.org/wiki/Activity_coefficient

    In thermodynamics, an activity coefficient is a factor used to account for deviation of a mixture of chemical substances from ideal behaviour. [1] In an ideal mixture, the microscopic interactions between each pair of chemical species are the same (or macroscopically equivalent, the enthalpy change of solution and volume variation in mixing is zero) and, as a result, properties of the mixtures ...