## Gibbs Free Energy

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

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

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

eduardomorales5
Posts: 77
Joined: Fri Aug 30, 2019 12:15 am

### Gibbs Free Energy

If the Gibbs free energy value is positive, does it also imply that the reaction is endothermic? Or could the reaction also be exothermic?

005391550
Posts: 103
Joined: Thu Jul 25, 2019 12:15 am

### Re: Gibbs Free Energy

if the change in gibbs free energy is positive, it does not necessarily mean that delta H (enthalpy) is positive or negative because it also takes into account temperature and entropy. a reaction is endothermic if delta H is positive and exothermic if delta H is negative.

Justin Quan 4I
Posts: 104
Joined: Sat Sep 14, 2019 12:17 am

### Re: Gibbs Free Energy

To add on, if ∆G is positive, then the forward reaction is non-spontaneous. Whether or not a reaction is endothermic or exothermic is dependent on ∆H. If you were giving ∆G & ∆S, then you can use the equation ∆G = ∆H - T∆S to predict if the reaction is endothermic or exothermic. However, just knowing ∆G alone does not imply anything about ∆H.