## Pressure

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

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

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

ng1D
Posts: 43
Joined: Wed Sep 18, 2019 12:17 am

### Pressure

Does pressure affect free energy? If it does how?

Posts: 81
Joined: Fri Aug 09, 2019 12:17 am

### Re: Pressure

The standard Gibbs Free Energy is calculated using the free energy of formation of each component of a reaction at standard pressure.

The Gibbs free energy equation is dependent on pressure. When a system changes from an initial state to a final state, the Gibbs free energy (ΔG) equals the work exchanged by the system with its surroundings, minus the work of the pressure force.

Delaney Smith 1C
Posts: 52
Joined: Thu Feb 28, 2019 12:15 am

### Re: Pressure

Yes, if you increase the partial pressure of a product gas, ΔG becomes more positive. If you increase the partial pressure of a reactant gas, ΔG becomes more negative because of the equation ΔG=ΔGo+RTlnQ where Q equals partial pressure of products over the partial pressure of reactants.

Matt F
Posts: 100
Joined: Sat Aug 17, 2019 12:17 am

### Re: Pressure

So in other words, pressure affects Gibbs Free Energy because it affects the value of Q?