Hi Kelsiu,

Just some thoughts...

TdS = dU -pdV is one of the Gibb's Equations (Tds = dH + Vdp is the second Gibb's Equation - for

simple compressible substances). Some call the Gibb's Equations, "property relations."

My understanding is these equations are not a combination of the First and Second Law. Were they a "combination" they would simply be an extension of those laws and therefore NOT constitute independent

information.

For the mass equation (some say "conservation of mass equation")

For the momentum eqn, energy eqn ... All properties relate directly the matter of the system.

The Second Law is unique in that its "system" is the universe.

The properties of its equation belong some to the system, some to the surroundings.

I have a page about Entropy. Sorry it is in a "draft" stage. Perhaps of use.

http://www.thermospokenhere.com/wp/0...t_entropy.html
Good luck with your studies! TSH