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

AI Thread Summary
In reversible processes, the change in entropy of the system and surroundings can indeed be zero, but this is not limited to isothermal conditions. Adiabatic processes can also be reversible, demonstrating that temperature does not need to remain constant for entropy changes to balance. The discussion highlights that both isothermal and adiabatic reversible processes can achieve a total entropy change of zero. Additionally, the conditions for zero total entropy change are clarified through integrals of heat transfer over temperature. Understanding these nuances is crucial for accurately interpreting thermodynamic principles.
kntsy
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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!
 
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kntsy said:
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!
No. An adiabatic process (eg. expansion or compression) can be reversible. In such a case, the temperature is not constant.

AM
 


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

AM

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