Equilibrium constant

The standard equilibrium constant, K⊖(T), for a chemical reaction is a dimensionless quantity defined by K⊖(T)=exp{−ΔrG⊖(T)/RT}, where ΔrG⊖(T) is the change in the standard molar Gibbs energy due to the reaction. The value of K⊖(T) depends on the choice of the standard state, which must be specified. The standard equilibrium constant is, like all standard thermodynamic quantities, independent of pressure and composition (Ewing et al. 1994; Cohen et al. 2008)