# What is the difference between the chemical potential μ and the molar Gibbs free energy Gm?

I'm not too sure if I understand this correctly:
Is the $G_\mathrm{m}$, the Gibbs free energy of the entire system, divided by the amount of substance making up the system, while $\mu$ is the Gibbs free energy of a component of the system?

If so, what does ${\partial G_\mathrm{m}}/{\partial n}=\mu$ signify? As in, what's the difference between this and $\mathrm{d}G/\mathrm{d}n=\mu$?

• @orthocresol Any particular reason you removed the subscripted unicode m? – Martin - マーチン May 27 '16 at 9:25
• @Martin i.imgur.com/0GueIzJ.png – orthocresol May 27 '16 at 11:20
• @orthocresol O.ô Guess you have some missing fonts then. Can you read any of the wikipedia page on unicode sub/superscript? (Also you just triggered a rollback war auto flag, lol.) – Martin - マーチン May 27 '16 at 11:32
• @Martin oops, sorry! Well, about two-thirds of the symbols are fine, the others don't appear. The subscripted numbers work (so chemical formulae in titles tend to work) – orthocresol May 27 '16 at 14:23
• You are thinking in the right direction, but it has no mathematical sense. Now there is a misunderstanding of derivatives :-) We can fix $T$ and $p$ in a system, but $\partial G / \partial T$ (or $p$) won't be null, because they represent how $G$ would change if in infinitesimal change in $T$ (or $p$) is performed. – user1420303 May 27 '16 at 15:54