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  2. Van 't Hoff equation - Wikipedia

    en.wikipedia.org/wiki/Van_'t_Hoff_equation

    where ln denotes the natural logarithm, is the thermodynamic equilibrium constant, and R is the ideal gas constant.This equation is exact at any one temperature and all pressures, derived from the requirement that the Gibbs free energy of reaction be stationary in a state of chemical equilibrium.

  3. Gibbs free energy - Wikipedia

    en.wikipedia.org/wiki/Gibbs_free_energy

    Its symbol is Δ f G˚. All elements in their standard states (diatomic oxygen gas, graphite, etc.) have standard Gibbs free energy change of formation equal to zero, as there is no change involved. Δ f G = Δ f G˚ + RT ln Q f, where Q f is the reaction quotient. At equilibrium, Δ f G = 0, and Q f = K, so the equation becomes Δ f G˚ = − ...

  4. Equilibrium constant - Wikipedia

    en.wikipedia.org/wiki/Equilibrium_constant

    This equation can be used to calculate the value of log K at a temperature, T 2, knowing the value at temperature T 1. The van 't Hoff equation also shows that, for an exothermic reaction ( Δ H < 0 {\displaystyle \Delta H<0} ), when temperature increases K decreases and when temperature decreases K increases, in accordance with Le Chatelier's ...

  5. Gibbs–Helmholtz equation - Wikipedia

    en.wikipedia.org/wiki/Gibbs–Helmholtz_equation

    The definition of the Gibbs function is = + where H is the enthalpy defined by: = +. Taking differentials of each definition to find dH and dG, then using the fundamental thermodynamic relation (always true for reversible or irreversible processes): = where S is the entropy, V is volume, (minus sign due to reversibility, in which dU = 0: work other than pressure-volume may be done and is equal ...

  6. Transition state theory - Wikipedia

    en.wikipedia.org/wiki/Transition_state_theory

    Using the Eyring equation, there is a straightforward relationship between ΔG ‡, first-order rate constants, and reaction half-life at a given temperature. At 298 K, a reaction with ΔG ‡ = 23 kcal/mol has a rate constant of k ≈ 8.4 × 10 −5 s −1 and a half life of t 1/2 ≈ 2.3 hours, figures that are often rounded to k ~ 10 −4 s ...

  7. Binding constant - Wikipedia

    en.wikipedia.org/wiki/Binding_constant

    The binding constant, or affinity constant/association constant, is a special case of the equilibrium constant K, [1] and is the inverse of the dissociation constant. [2] It is associated with the binding and unbinding reaction of receptor (R) and ligand (L) molecules, which is formalized as:

  8. Exergonic reaction - Wikipedia

    en.wikipedia.org/wiki/Exergonic_reaction

    The change of Gibbs free energy (ΔG) in an exergonic reaction (that takes place at constant pressure and temperature) is negative because energy is lost (2). In chemical thermodynamics, an exergonic reaction is a chemical reaction where the change in the free energy is negative (there is a net release of free energy). [1]

  9. Chemical equilibrium - Wikipedia

    en.wikipedia.org/wiki/Chemical_equilibrium

    In order to meet the thermodynamic condition for equilibrium, the Gibbs energy must be stationary, meaning that the derivative of G with respect to the extent of reaction, ξ, must be zero. It can be shown that in this case, the sum of chemical potentials times the stoichiometric coefficients of the products is equal to the sum of those ...