## Spontaneous

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

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

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

Brandon Mo 4K
Posts: 70
Joined: Fri Sep 28, 2018 12:15 am

### Spontaneous

When is a reaction spontaneous in terms of Gibbs Free Energy, enthalpy, and entropy?

What does being spontaneous actually mean?

Kevin ODonnell 2B
Posts: 62
Joined: Fri Sep 28, 2018 12:24 am

### Re: Spontaneous

Basically we can just use Gibbs to relate all three terms and determine if something is spontaneous or not
Remember the Gibbs equation is (delta)G = (delta)H - T(delta)S
Gibbs Free Energy = if it is negative it is spontaneous
Spontaneous = a reaction that favors the formation of products under the current conditions
The attached picture will help to explain when enthalpy and entropy lead to a spontaneous reaction in reference to the Gibbs Free Energy equation stated above:
Attachments

Ray Huang 1G
Posts: 30
Joined: Fri Sep 28, 2018 12:20 am

### Re: Spontaneous

Reactions are spontaneous as long as Gibbs free energy is negative. The other values can be any combination of signs as long as the resulting Gibbs free energy value is negative.