Ppt Question

[Jessica Chen 2C]

For the question on slide 5 of the final review PowerPoint, why do we only use the delta G for PCl5 and PCl3 when calculating the delta G of the reaction?

[Katie Kyan 2K]

This is because the standard gibbs free energy for Cl2 is 0 as diatomic molecules are already in their standard state. Thus when calculating the delta G of the reaction we exclude the delta G for Cl2 since it is 0.

[Frank He 4G]

I think it might be because the gibbs free energy of formation for Cl2 is 0, since it's already in its most stable form.