## Gibbs equation

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

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

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

Netpheel Wang 4L
Posts: 60
Joined: Fri Sep 28, 2018 12:15 am

### Gibbs equation

In terms of this new equation, does it mean that deltaH negative no longer implies spontaneous reactions?

Seohyun Park 1L
Posts: 73
Joined: Fri Sep 28, 2018 12:29 am

### Re: Gibbs equation

Delta H negative does not always mean a spontaneous reaction as entropy plays a part. If the entropy of the system decreases and the temperature is high enough, an exothermic reaction could be non spontaneous as the TOTAL entropy (entropy of system + surroundings) is decreasing.

marisaimbroane1J
Posts: 69
Joined: Fri Sep 28, 2018 12:23 am

### Re: Gibbs equation

The spontaneity of a reaction is determined from delta G. Even though a negative delta H is favorable, it does not always mean the reaction will be spontaneous. Any time delta G is negative, the reaction is spontaneous.