As I understand, during the process of phase change from a liquid to solid (or any phase change for that matter,) the temperature of the substance remains constant as the energy being applied to the substance is used in changing phase.
How does this relate to Gibbs free energy? I read that [itex]\Delta G[/itex] during melting is zero. Enthalpy and entropy, however, increase. Does this have any relation to the uniformity of the temperature of the substance during the change of phase?
I'm led to believe that [itex] \Delta G > 0[/itex] when phase change isn't taking place because of the changing temperature. (For example, when the temperature of water is raised from 30°C to 50°C.) How accurate is this assumption?