The point in a one-component system at which the temperature and pressure of three phases are in equilibrium. If there are
possible phases, there are
triple points.
Example: In the sulfur system four possible triple points (one
metastable) exist for the four phases comprising rhombic
S
(solid), monoclinic
S (solid),
S (liquid) and
S (vapour).
Source:
PAC, 1994, 66, 577
(Definitions of terms relating to phase transitions of the solid state (IUPAC Recommendations 1994))
on page 593
Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
doi:10.1351/goldbook.
