How Does the Total Derivative of Gibbs Free Energy Change in a Closed System?

[Lindsayyyy]

Hi everyone

Homework Statement

Let's say I want to do the totale drivative of the Gibbs free energy in dependent of: volume, temperature, amount of substance and surface. And let's say afterwards we have a closed system where the temperature is constant. How does the total derivative change?

Homework Equations

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The Attempt at a Solution

I guess I know that the amount of substance doesn't change in a closed system, so my dn=0 and this part gets lost, also dT=0. But I'm not sure about the surface, does that change aswell? I think the Volume can't be disregarded.

Thanks for your help

 

[HallsofIvy]

If all you are given is that the temperature is constant, I would see no reason to assume that volume or "surface" are constant.

(What, exactly, do you mean by "surface"? All other variables you mention are numbers.)