## equation explanation

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

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

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

Jane Burgan 1C
Posts: 73
Joined: Fri Sep 28, 2018 12:15 am

### equation explanation

Hi can someone explain the equation G = deltaG^0 + RTlnQ? I'm not sure where the RTlnQ is coming from.

ThomasLai1D
Posts: 61
Joined: Fri Sep 28, 2018 12:17 am

### Re: equation explanation

RTlnQ is derived from the deltaG^0 = -RTlnK. K represents the system in the standard state at equilibrium, so if you want to find deltaG not at equilibrium, you must use Q in the equation and subtract it from -RTlnK.

PranitKumaran1F
Posts: 30
Joined: Thu Nov 08, 2018 12:17 am

### Re: equation explanation

deltaG^0 refers to the Gibbs free energy of a reaction in equilibrium, but RTlnQ is used to find the Gibbs free energy of a reaction that is not in equilibrium, which can be shown through the fact that the Q of a reaction is the ratio of products to reactants for reactions that may or may not be in equilibrium.