## Standard Gibbs Free Energy of Formation (Units)

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

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

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

Grace Han 2K
Posts: 33
Joined: Tue Nov 15, 2016 3:00 am

### Standard Gibbs Free Energy of Formation (Units)

When calculating for the standard gibbs free energy of formation, what are the units? Is it Kj or Kj/mole?

I thought the answer would be in kilojoules or joules because the moles cancel out when you multiply with n, but the answer in self-test 9.21A has it in kj/mol.
In example 9.14, its answer is left in kJ.

Suchita 2I
Posts: 59
Joined: Fri Sep 29, 2017 7:04 am

### Re: Standard Gibbs Free Energy of Formation (Units)

The units would depend on the number of moles in the calculation. If the calculation was done for 1 mole, it would be kJ/mol, but otherwise report it in kJ.

RohanGupta1G
Posts: 34
Joined: Sat Jul 22, 2017 3:00 am

### Re: Standard Gibbs Free Energy of Formation (Units)

As Suchita said, it depends on how the question is worded, and how you complete the calculations, however kj/mole should be good.