## Thermodynamic Stability

$\Delta G^{\circ}= \Delta H^{\circ} - T \Delta S^{\circ}$

$\Delta G^{\circ}= -RT\ln K$

$\Delta G^{\circ}= \sum \Delta G_{f}^{\circ}(products) - \sum \Delta G_{f}^{\circ}(reactants)$

Giselle Littleton 1F
Posts: 78
Joined: Wed Sep 18, 2019 12:20 am

### Thermodynamic Stability

Why is a compound considered to be thermodynamically stable when △G°is negative and thermodynamically unstable when △G°is positive?

Alex Tchekanov Dis 2k
Posts: 118
Joined: Sat Aug 24, 2019 12:16 am

### Re: Thermodynamic Stability

When the standard Gibbs free energy of formation is considered thermodynamically stable when it is negative because the pure compound is then considered to have a lower Gibbs free energy than the Gibbs free energy of the pure elements which would mean that the pure element would have the tendency to turn into the pure compound at that specific temperature.

When the standard Gibbs free energy of formation is positive it is considered thermodynamically unstable where the pure compound would have the tendency to decompose/revert back to the pure element at that specific temperature.