Thermodynamic Equilibrium:Adiabatic and Isochoric System.

Adiabatic and Isochoric System

For an adiabatic system, we have Q˙ = 0 and thus

Entropy grows in an adiabatic process, until it reaches a maximum in equilibrium. We note that for an isochoric process, where V = const., or dV = 0, the total energy E = U + Epot stays constant as well. Thus, we have in particular

Indeed, this is the case of a fully isolated system as discussed above, which does not exchange heat and work with its surroundings. The equilibrium state for this case follows from maximizing entropy under constraints of given values for mass m and energy U + Epot.