## Energy calculation precision

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

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

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

JennyCKim1J
Posts: 51
Joined: Fri Sep 29, 2017 7:04 am

### Energy calculation precision

Out of three methods for calculating free energy, which one is the most accurate/least accurate and why?

Deap Bhandal L1 S1J
Posts: 77
Joined: Fri Sep 29, 2017 7:05 am
Been upvoted: 2 times

### Re: Energy calculation precision

There is actually a fourth equation too which derives delta g from a standard state cell potential: delta G= (-)moles of electrons*faraday's constant*cell potential. Depending on what information is given will tell you which equation to use. The accuracy of them depends on how accurate and precise the variables are in them. Otherwise, they should give very similar delta Gs.

Justin Chang 2K
Posts: 53
Joined: Fri Sep 29, 2017 7:04 am

### Re: Energy calculation precision

I don't think Dr. Lavelle has told us which one is most/least accurate of the three methods, so I wouldn't worry about it unless he says it in lecture sometime. You will just have to calculate deltaG based on the information that is given to you (if you have deltaH, deltaS, and a temperature, then use G=H-TS, and etc)