## pressure and free energy

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

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

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

Irma Ramos 2I
Posts: 51
Joined: Fri Sep 29, 2017 7:07 am

### pressure and free energy

I'm a little confused as to when we use the Gibbs free energy equation that includes pressure? Are we going to be told to use it in a question or do we have to know when to use it by our own knowledge?

Gurshaan Nagra 2F
Posts: 49
Joined: Thu Jul 27, 2017 3:01 am

### Re: pressure and free energy

When they ask you to calculate the Gibbs free energy at certain partial pressures is when you use it. It just depends on what they give you in the question.

Wenxin Fan 1J
Posts: 53
Joined: Thu Jul 13, 2017 3:00 am

### Re: pressure and free energy

Questions will normally specify if pressure has changed or if a reaction is not at standard conditions. That is when you would use that version of the gibbs free energy equation.