Supercritical

Definition

A supercritical fluid is a substance at a temperature and pressure above its critical point, where distinct liquid and gas phases do not exist. It exhibits unique properties that are intermediate between those of gases and liquids.

5 Must Know Facts For Your Next Test

1. Supercritical fluids have densities similar to liquids but viscosities like gases, allowing for unique solvation properties.
2. The critical point is the highest temperature and pressure at which a substance can exist as a liquid and gas in equilibrium.
3. Above the critical point, small changes in temperature or pressure result in significant changes in density, leading to highly tunable solvents.
4. Supercritical carbon dioxide (scCO2) is commonly used in industrial applications due to its non-toxic and non-flammable nature.
5. In thermodynamics, supercritical fluids are studied for their ability to enhance reaction rates and improve heat transfer efficiency.

Review Questions

• What are the primary characteristics of a supercritical fluid?
• How does the behavior of a supercritical fluid compare to that of traditional liquids and gases?
• Why is supercritical carbon dioxide frequently used in industrial processes?

Related terms

Critical Point:

The specific temperature and pressure at which the phase boundary between liquid and gas disappears.

Phase Transition: A transformation from one state of matter (solid, liquid, gas) to another.

Kinetic Theory of Gases:

A theory that explains the macroscopic properties of gases in terms of the motion of individual molecules.