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No change in entropy of the system+surroundings in reversible process.Really?

  1. Sep 24, 2010 #1
    No change in entropy of the system+surroundings in "reversible" process.Really?

    This is a challenge to the sentense from some basic text.
    I think reversible is not enough.
    It has to be ISOTHERMAL, right?
    Lets me be sure that i am correct!
     
  2. jcsd
  3. Sep 24, 2010 #2

    Andrew Mason

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    Science Advisor
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    Re: No change in entropy of the system+surroundings in "reversible" process.Really?

    No. An adiabatic process (eg. expansion or compression) can be reversible. In such a case, the temperature is not constant.

    AM
     
  4. Sep 25, 2010 #3
    Re: No change in entropy of the system+surroundings in "reversible" process.Really?

    Thanks! But what about REVERSIBLE isobaric, isovolume,? The total system+environment change in entropy still can remain zero????
    I discover an important fact:
    [tex]\triangle S_{total}=\triangle S_{in} +\triangle S_{out}=0[/tex]
    iff
    [tex]\int\frac{dq_{in}}{T}=\int\frac{dq_{out}}{T}[/tex]
    iff
    reversible isothermal or adabiatic!!!!!!!
     
    Last edited: Sep 25, 2010
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