|
| |
| |
| Pressure - Temperature (P-T) Diagram |
A common graphic used to illustrate the relationship of substances in their phase states as a function of pressure and temperature is the P-T diagram. It is also referred to as a phase state diagram or a phase change diagram. The asterisk in the P-T diagram below identifies a pressure-temperature combination that is known as the triple point. That is where the substance can exist as a solid, a liquid, or a vapor.

P-T Diagram for a Substance That Expands On Freezing
| From | To | Phase Changes | | Liquid | Solid | Fusion | | Liquid | Vapor | Vaporization | | Solid | Vapor | Sublimation | | Solid | Liquid | Melting | | Vapor | Liquid | Condensation | | Vapor | Solid | Deposition |
. Critical Point: | Pure vapor phase has same properties as pure liquid phase at same temperature and pressure. | * Triple Point: | Possible to maintain equilibrium mixture of all three phases. |
| |
|
|
|