Entropy of isochoric process


An isochoric process, also called a constant-volume process, an isovolumetric process, or an isometric process, is a thermodynamic process during which the volume of the closed system undergoing such a process remains constant. An isochoric process is exemplified by the heating or the cooling of the contents of a sealed, inelastic container: The thermodynamic process is the addition or removal of heat; the isolation of the contents of the container establishes the closed system; and the inability of the container to deform imposes the constant-volume condition. The isochoric process here should be a quasi-static process. For heating or cooling of any system (gas, liquid or solid) at constant volume from an initial temperature T0 to a final temperature T, the entropy change is as shown here.

Related formulas


ΔSChange in Entropy (J*mole/K)
nnumber of moles (mole)
Cvheat capacity at constant volume (J/K)
TFinal Temperature (K)
T0Initial Temperature (K)