Definition of phase rule in US English:

phase rule


  • A rule relating the possible numbers of phases, constituents, and degrees of freedom in a chemical system.

    • ‘For simple systems, the Gibbs phase rule limits the conditions at which multiple phases can coexist at equilibrium.’
    • ‘For lipid mixtures the phase rule allows a temperature interval in which water may be in equilibrium with gel and fluid lipid domains.’
    • ‘Briefly, if one collapse point is observed for a mixed film (in which individual components have differentiated collapse pressures) the surface phase rule determines lateral miscibility in the film.’
    • ‘V. M. Goldschmidt at the University of Oslo applied the phase rule to mineralogical changes brought about during contact metamorphism of sedimentary rocks.’
    • ‘In 1887 Hendrik Willem Bakhuis Roozeboom applied Josiah Willard Gibb's phase rule to alloys.’