Suppose the entropy associated with the system and the surrounding at the start of thermodynamic process is $S_o$ and the entropy associated with it at the end is$S$. $$∆S=S-S_o$$

The entropy change through any reversible path connecting intial and final state can be given as- $$∆S_{rev}=\int\frac{dq}{T}$$

Suppose the entropy associated with the system and the surrounding at the start of thermodynamic process is $S_o$ and the entropy associated with it at the end is$S$. $$∆S=S-S_o$$

The entropy change through any reversible path connecting intial and final state can be given as- $$∆S_{rev}=\int\frac{dq}{T}$$ Here , $T$ is thermodynamic temperature.