Condensed Phases
Definition and meaning of Condensed Phases in chemistry.
Condensed phases are the solid and liquid states of matter, in which particles sit close together and are held by strong intermolecular or interatomic forces, unlike the gas phase where particles are widely separated and mostly non-interacting.
In more detail
Because particle spacing in solids and liquids is on the order of the particles' own size, cohesive forces such as van der Waals interactions, hydrogen bonding, ionic attraction, or metallic bonding dominate their physical behavior. This close packing gives condensed phases much higher densities and far lower compressibility than gases, since there is little empty space between particles to squeeze out. The term is central to physical chemistry when comparing phase behavior, discussing phase diagrams, vapor pressure equilibria, or the transition between a condensed phase and its vapor.
Key facts
| Field | Physical Chemistry |
|---|---|
| States included | Solid and liquid |
| Key property | High density, low compressibility |
| Contrasted with | Gas phase |
Liquid water (H2O(l)) and solid ice are both condensed phases; heating ice past 0 degrees C melts it to liquid water, and heating the liquid past 100 degrees C (at 1 atm) converts it to water vapor, the corresponding gas phase.
Frequently asked questions
Why are solids and liquids grouped together as condensed phases?
Because in both, particles are packed close together and interact strongly, giving similar density and compressibility behavior that sharply contrasts with gases.
Is plasma considered a condensed phase?
No. Plasma consists of widely spaced, ionized particles and behaves more like an extreme gas, so it is not classified as a condensed phase.