# Why is Gibbs free energy 0 at phase change?

However, since the Gibbs function depends naturally on the Thermodynamic variables $p$ and $T$ and since common phase transitions occurs at a constant $p$ and $T$, thus, the molar/specific Gibbs function tends to be a constant during the phase change.
Thus, change in the Gibbs function is zero, i.e. $\mathrm{dG} = 0$ even though the molar/specific Gibbs function is non zero.