1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

I Why is entropy a state variable even for irreversible path?

  1. Mar 17, 2017 #1

    The entropy S is a state variable or state function as the integral of dS = dQ/T is a path-independent, provided that the path is reversible process path. However, such a path-independency of the integral breaks down when the path includes irreversible process. So, I guess we can only say that S is a state variable only if there is no irreversible process, but the textbook said S is the state variable no matter the process includes irreversible process or not.

    Well..if there is at least one irreversible process path along which the path-independency doesn't hold, how can I justify that S is a state variable?

    I would like to get your help to clarify this confusion.
  2. jcsd
  3. Mar 17, 2017 #2
    Suppose you had an irreversible process path that took your system from thermodynamic equilibrium state A to thermodynamic equilibrium state B. How would you determine the change in entropy for your system?
  4. Mar 18, 2017 #3
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted