# Thermodynamics & PV work relationships

1. Sep 26, 2013

### speny83

Hi all, studying for a physical chemistry exam tomorrow morning and I'm getting really confused. I am hoping somebody has an easy to understand explanation of How alot of this stuff works.

specifically the relationships between ΔH, ΔU, q & W and constan P,V & T
i.e. if P is constant how these relate VS If T is constant.

I understand the derivations of Heat transfer for constant P=constant and V= constant; as well as Wrev and wirr

also, I know the ΔU=w+q and dH=dU+d(pv)....is this last one the trick to finding U and H for given process?

I guess i dont really have a question, just pumping so much stuff into my head its all spinning around in circles and hoping someone can provide a couple statements that get me back on track.

Maybe a good place to start is if you could clearly explain when/where/why Δ_=0 for some of the above, i think maybes that where i getting all mixed up.

As always I really appreciate you helpful folks on this forum! Thanks.

Last edited: Sep 26, 2013