Linked from
The 14 pages that link to Phase equilibrium, each with the reason it gives.
Chemical potentialRelated: A species has equal chemical potential in every phase at equilibrium.
Vapor pressureRelated: Vapor pressure is defined by coexistence of vapor with liquid or solid.
Thermodynamic potentialRelated: Equal chemical potentials across phases characterize equilibrium.
AmphiboleRelated: Pressure, temperature, and fluid composition determine which amphiboles can form.
Unit operationRelated: Equilibrium limits the separation achievable in distillation and extraction.