A relationship analogous to the isokinetic relationship but applied to equilibrium data. The equation defining the isoequilibrium temperature β is: \[\Delta _{\text{r}}H - \beta\ \Delta _{\text{r}}S = \text{constant}\] where ΔH and ΔS are enthalpy and entropy of reaction, respectively.
Source:
PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1128 (https://doi.org/10.1351/pac199466051077)