For isothermal, isobaric systems it is always at a local minimum in order for equilibrium to be stable, and the value of this quantity remains constant across a phase transition.
This quantity is is related to the mole fraction of compounds and temperature-dependent parameters through the Redlich-Kister expansion. The definition of fugacity involves a calculation subtracting the value of this quantity for an ideal gas from its actual value at the same temperature and pressure. For a liquid, the derivative of this quantity with respect to area is directly related to the (*) surface tension. For isothermal, isobaric systems it is always at a local minimum in order for equilibrium to be stable, and the value of this quantity remains constant across a phase transition. For 10 points, name this quantity equal to H minus TS or PV plus the Helmholtz energy.
This quantity is is related to the mole fraction of compounds and temperature-dependent parameters through the Redlich-Kister expansion.
Gibbs free energy [accept Excess Gibbs free energy until "fugacity"]