## Gibbs Free Energy calculation

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

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

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

504939134
Posts: 103
Joined: Wed Sep 18, 2019 12:21 am

### Gibbs Free Energy calculation

Will we only be using the Gibbs change in free energy equation? And when do we know to use it instead of just G=H-TS?

Eesha Sohail 1D
Posts: 100
Joined: Sat Aug 17, 2019 12:16 am

### Re: Gibbs Free Energy calculation

It depends on the values/units you are given in the question. If reaction constant is given (which, probably not) then you will most likely use the other equation. However, the G = H-TS equation is definitely the most important one.

Alison Trinh 1E
Posts: 104
Joined: Thu Jul 25, 2019 12:16 am

### Re: Gibbs Free Energy calculation

Why do we need to use the concept of Gibbs Free Energy?

Ashley Fang 2G
Posts: 102
Joined: Fri Aug 30, 2019 12:17 am

### Re: Gibbs Free Energy calculation

We need to know the concept of Gibbs free energy because it tells us whether a reaction will be spontaneous or not.
If delta G is negative, the reaction is spontaneous, and the products will have less free energy than the reactants.
If delta G is positive, the reaction is NOT spontaneous, and the products will have more free energy than the reactants.