Homework Help: Constraints on the Gibbs Equation, Tds = dh - vdP

1. The problem statement, all variables and given/known data
What constraints are imposed on the use of the Gibbs equation Tds = dh - vdP


2. Relevant equations

Tds = dh - vdP

3. The attempt at a solution

I seem to be stuck on this question. So far I have come up with the following constraints, but I'm not even sure if they are correct:

1. The equation holds for only closed systems at constant pressure
2. The equations holds only for systems in which the free energy depends only on P and T.
3. The equation doesn't apply on mixtures or supercooled liquids.