## Equilibrium Constant and Gibbs Free Energy

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

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

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

Ashley Kenney 1E
Posts: 32
Joined: Wed Nov 14, 2018 12:23 am

### Equilibrium Constant and Gibbs Free Energy

I'm a little confused as to how the equation $\Delta G^{\circ}=-RTlnK$ is derived.
Where does the equilibrium constant come from in this equation? Thanks!

Ashe Chen 2C
Posts: 31
Joined: Mon Jan 07, 2019 8:23 am

### Re: Equilibrium Constant and Gibbs Free Energy

If Gr$\neq$Gp, then the rxn is not at equilibrium and:
$\Delta G = \Delta G^{\circ}+ RTlnQ$
At Equilibrium, $\Delta G$ = 0
Resulting in $\Delta G^{\circ} = -RTlnK$

Yousif Jafar 1G
Posts: 59
Joined: Thu May 10, 2018 3:00 am

### Re: Equilibrium Constant and Gibbs Free Energy

The equilibrium constant only comes into play when we use this equation at equilibrium

Henry_Phan_4L
Posts: 68
Joined: Fri Sep 28, 2018 12:24 am

### Re: Equilibrium Constant and Gibbs Free Energy

What is the difference between the delta G with the degree sign and the total G?