[tenbee]

Is Gibbs Free Energy the energy available to do non-PV work?

If this is true... is that because Gibbs Free Energy is dependent on enthalpy, which is the sum of internal energy/heat and PV-work?

[zaphraud]

Well, its a good rule of thumb when dealing with bulk amounts of simple chemicals, to determine reaction rates, equilibrium, amount of energy that can be generated via a certain reaction, etc.

The "right" answer to your question likely depends on if the question is being asked from the standpoint of a particular situation, or from the standpoint of a homework question; exceptions are the expected result in chemistry, and it is the exceptions to the general rules where the most interesting observations are made.