## Spontaneity

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

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

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

Donna Nguyen 2L
Posts: 100
Joined: Sat Aug 24, 2019 12:17 am

### Spontaneity

How does Gibbs Free Energy relate to spontaneity?

alex_4l
Posts: 109
Joined: Thu Sep 26, 2019 12:18 am

### Re: Spontaneity

When delta G is negative = it is spontaneous in the forward direction and non-spontaneous in the reverse direction
When delta G is 0 = this is equilibrium so the reaction is reversible, this means that the rate of the forward reaction is equal to the rate of the reverse reaction
When delta G is positive = the reaction is non-spontaneous in the forward direction and spontaneous in the reverse direction

Hope that helps!

kim 2I
Posts: 105
Joined: Thu Jul 25, 2019 12:17 am

### Re: Spontaneity

An exothermic reactions is spontaneous because it results in an increase of entropy of the surroundings. If you think of the equation △Gr= △Hr-T △Sr, when △Hr is large enough and negative compared to △Sr, the Gibbs Free Energy would be negatvie and therefore making the reaction spontaneous.

preyasikumar_2L
Posts: 101
Joined: Fri Aug 09, 2019 12:17 am

### Re: Spontaneity

△G < 0 means that the forward reaction is spontaneous, exothermic
△G = 0 means that the reaction is at equilibrium, reversible
△G > 0 means that the forward reaction is not spontaneous, endothermic