Proper noun
the Gibbs-Helmholtz equation
(thermodynamics) An equation for calculating changes in the Gibbs free energy of a system as a function of temperature:
(
∂
(
G
T
)
∂
T
)
p
=
−
H
T
2
,
{\displaystyle \left({\frac {\partial \left({\frac {G}{T}}\right)}{\partial T}}\right)_{p}=-{\frac {H}{T^{2}}},}
where H is the enthalpy, T the absolute temperature and G the Gibbs free energy of the system, all at constant pressure p.