First-Order Phase Transformation at Constant Volume: A Continuous Transition?

ABSTRACT: We describe a first-order phase transition of a simple system in a process where the volume is kept constant. We show that, unlike what happens when the pressure is constant, (i) the transformation extends over a finite temperature (and pressure) range, (ii) each and every extensive potential (internal energy U, enthalpy H, Helmholtz energy F, and Gibbs energy G), and the entropy S is continuous across the transition, and (iii) the constant-volume heat capacity does not diverge during the transition and only exhibits discrete jumps. These non-intuitive results highlight the importance of controlling the correct variables in order to distinguish between continuous and discontinuous transitions. We apply our results to describe the transition between ice VI and liquid water using thermodynam

SUBMITTER: Correa VF 

PROVIDER: S-EPMC8774774 | biostudies-literature | 2021 Dec

REPOSITORIES: biostudies-literature