Gibb's Energy and Work

[Leah Savage 2F]

Is Gibb's free energy only for nonexpansion work?
What is the relationship between gibb's free energy and work? what kind of system is w=-P(deltaV) for if it's not for reversible/irreversible processes? Irreversible/reversible processes do expansion work, right?

[Michelle Chernyak 1J]

w=-PdeltaV applies to the work done in a irreversible expansion and yes both irreversible and reversible processes do expansion work, there are just two different equations used to solve for w.

[Austin Ho 1E]

I don't think Gibb's Free Energy is only for non-expansion work. Both systems with irreversible and reversible processes can do expansion work. In theory, ΔG=wmax, or the maximum amount of work that can be done is ΔG.

In an irreversible expansion, w=-PΔV; pressure is constant while volume changes. This is because we suddenly change pressure, and wait for volume to shift accordingly.

In a reversible expansion, w=-nRTln(V2/V1); temperature is constant while pressure and volume change simultaneously. This is because external pressure is slowly being adjusted to make the changes infinitesimally small, and thus reversible.

Hope this helps.

[Susie Lee 2I]

Gibbs Free Energy measures the useful work obtainable from a thermodynamic system at a constant temperature and pressure.

[Rishi Khettry 1L]

Gibbs free energy does not apply only to nonexpansion work