I Adiabatic irreversible process vs adiabatic reversible

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In an adiabatic irreversible process, a thermodynamic system experiences a positive change in entropy as it moves from state A to state B. This change in entropy, denoted as S_g, indicates that heat must be transferred to the surroundings. In contrast, a reversible adiabatic process between the same states cannot occur without heat flow, as the entropy change ΔS must be accounted for. Therefore, if ΔS is greater than zero, some heat transfer is necessary during the reversible process. This understanding reinforces the relationship between entropy, heat flow, and the nature of thermodynamic processes.
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adiabatic irreversible vs adiabatic reversible processes between two given thermodynamic states
Hi,

consider an adiabatic irreversible process carrying a thermodynamic system from initial state A to final state B: this process is accompanied by a positive change in system entropy (call it ##S_g##). Then consider a reversible process between the same initial and final system state. Such reversible process could be adiabatic itself ?

I believe not because the exceeding entropy between final and initial state (that are the same regardless the process) has to be transferred out to the surrounding by means of heat "crossing" the boundary of the system itself.

Does it make sense ? Thanks
 
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Yes. Since ##\Delta S = \int_A^B \frac{dQ_{rev}}{T}##, if ΔS > 0 then dQrev cannot be zero throughout: ie. there must be some heat flow during the reversible process from A to B

AM
 
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