Maths help

[Perfect Dark]

Hello all.

I would like help with this question if its ok.

Assuming that the free energy of a substance, G, is a function of pressure, p abd temperature, T, i.e G=G(p,T)

(a) write an expression for the total differential change in the free energy, dG.

(b) Comparing the results from above with the equation

dG = V dp - SdT

Write down expressions for
(i) (DeltaG/Deltap)T
and
(ii)(deltaG/DeltaT)p

small T and p are meant at X constant


Any help would be appreciated

[zaza]

Hm, can I recommend that you read "Equilibrium Thermodynamics" by Adkins or "Statistical Physics" by Mandl, like you're supposed to when you get stuck on a problem sheet? Or maybe even the lecture notes.
No offense, but you're really better off reading up on this stuff and making sense of it yourself, or handing in a duff set of answers, getting a bad mark and then getting some help, because it is fairly fundamental thermodynamics and you'll need it later.

You'll thank me.

[Harsh Gupta]

Hm, can I recommend that you read "Equilibrium Thermodynamics" by Adkins or "Statistical Physics" by Mandl, like you're supposed to when you get stuck on a problem sheet? Or maybe even the lecture notes.
No offense, but you're really better off reading up on this stuff and making sense of it yourself, or handing in a duff set of answers, getting a bad mark and then getting some help, because it is fairly fundamental thermodynamics and you'll need it later.

You'll thank me.

zaza,

i think it's pure Mathematics (differentiation and integration) which is used extensively in Physics. he is just asking for a differentiation of a function with 2 variables and then comparing it with a given equation to get the equations (or values) for V and S (or -S).

[zaza]

I know what he's after. But honestly, if you skip out on this stuff and don't get your head round it, then there's a lot of thermodynamics that isn't going to make a lot of sense.
The answers to these very questions are in just about every thermo textbook I've read, so fundamental and typical are they. It's worth looking up.

[Perfect Dark]

Thanks for the help guys