1
$\begingroup$

I read quite a few questions on this website dealing with the idea of demonstrating that entropy is a state function. None of the answers I read seemed to be fully conclusive. So my question is : is there anything wrong in saying that the second principle postulates the existence of entropy as a state function? Or is there a definitive demonstration showing that from a more restrictive statement of the second principle?

$\endgroup$
2
$\begingroup$

One complete description of the second law of thermodynamics is:

$\exists \quad S=S(U,V) \quad \textrm{with} \quad dS\geq0$

It indeed contains the existence of entropy as a state function. I for myself don't like the weird historical formulations.

$\endgroup$
3
  • $\begingroup$ This does not answerthe OP's question of whether the state function property of entropy is just a postulate or does it have a proof? $\endgroup$ – user258881 Apr 4 '20 at 6:54
  • 1
    $\begingroup$ It doesn't have a thermodynamic proof. It is the foundation of thermodynamics. And it answers exactly what OP is looking for: yes it is part of the second law. Do you want me to show how other statements of the second law follow from this? $\endgroup$ – user224659 Apr 4 '20 at 8:53
  • $\begingroup$ @FakeMod I tried to clarify. $\endgroup$ – user224659 Apr 4 '20 at 8:58

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.