Exchanging roles of variable and thermal potential

  • #1
1,225
75

Main Question or Discussion Point

In thermal physics entropy S is regarded as a system variable in 1st theorem of thermal dynamics, i.e.
[tex]dE(S,V)=TdS-pdV=T(S,V)dS-p(S,V)dV[/tex]

Entropy is regarded also as thermal potential,i.e.

[tex]dS(E,V)=\frac{1}{T(E,V)}dE + \frac{p(E,V)}{T(E,V)}dV[/tex]

S,V,p,T are usually regarded as variables. My question is that other variables V, p, T can be also treated as thermal potentials ? Can exchanging roles of variable and thermal potential take place only for the pair of E and S ?
 

Answers and Replies

  • #2
1,225
75
[tex]dV(S,E)=\frac{T(S,E)}{p(S,E)}dS-\frac{1}{p(S,E)}dE[/tex]
[tex]dT(F,V)=\frac{p(F,V)}{S(F,V)}dV-\frac{1}{S(F,V)}dF[/tex]
[tex]dp(G,T)=\frac{1}{V(G,T)}dG+\frac{S(G,T)}{V(G,T)}dT[/tex]
where
[tex]F=E-TS[/tex]
[tex]G=E-TS+PV[/tex]

V,T and p are thermal potential as S is. Is it OK?
 

Related Threads on Exchanging roles of variable and thermal potential

Replies
2
Views
4K
Replies
18
Views
12K
  • Last Post
2
Replies
42
Views
13K
  • Last Post
2
Replies
25
Views
4K
Replies
4
Views
1K
  • Last Post
Replies
6
Views
2K
Replies
1
Views
2K
Replies
2
Views
4K
  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
4
Views
1K
Top