|
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,
which is where the substance can simultaneously exist as a solid, a liquid, or a vapor.
P-T Diagram for a Substance That Expands On Freezing
| Liquid |
Solid |
Fusion (aka Freezing) |
| 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. It is the highest
temperature at which a gas can be liquefied, regardless of pressure. |
 Triple Point: |
Possible to maintain equilibrium mixture of all three phases. |
Posted March 13, 2015
|
