Capracus
27th October 2011 - 09:20 AM
A phase is a region of space (a thermodynamic system), throughout which all physical properties of a material are essentially uniform.
Capracus
28th October 2011 - 04:27 AM
Examples of physical properties include density, index of refraction, and chemical composition.
Capracus
29th October 2011 - 05:54 AM
A simple description is that a phase is a region of material that is chemically uniform, physically distinct, and (often) mechanically separable.
Capracus
31st October 2011 - 03:04 AM
In a system consisting of ice and water in a glass jar, the ice cubes are one phase, the water is a second phase, and the humid air over the water is a third phase.
Capracus
31st October 2011 - 12:44 PM
The glass of the jar is another separate phase.
Capracus
1st November 2011 - 02:55 AM
The term phase is sometimes used as a synonym for state of matter.
Capracus
2nd November 2011 - 03:02 AM
Also, the term phase is sometimes used to refer to a set of equilibrium states demarcated in terms of state variables such as pressure and temperature by a phase boundary on a phase diagram.
Capracus
3rd November 2011 - 06:47 AM
Because phase boundaries relate to changes in the organization of matter, such as a change from liquid to solid or a more subtle change from one crystal structure to another, this latter usage is similar to the use of "phase" as a synonym for state of matter.