Fázisegyensúly

Fázisegyensúly refers to the state where a system contains multiple phases in equilibrium, meaning there is no net change in the amount or proportion of each phase over time. This concept is fundamental in thermodynamics and physical chemistry, particularly when dealing with substances that can exist in different physical states, such as solid, liquid, and gas.

At equilibrium, the chemical potential of each component is the same in all phases present. This equality of chemical potential drives the movement of matter between phases until a balance is reached. For a pure substance, fázisegyensúly occurs at specific temperatures and pressures. For example, at the melting point of ice, solid water (ice) and liquid water coexist in equilibrium. Similarly, at the boiling point, liquid water and gaseous water (steam) are in equilibrium.

The phase rule, developed by Josiah Willard Gibbs, quantifies the degrees of freedom in a system at fázisegyensúly. It relates the number of independent components, the number of phases, and the number of intensive variables (like temperature and pressure) that can be varied independently without changing the number of phases in equilibrium. Understanding fázisegyensúly is crucial for various applications, including material science, chemical engineering, and geology, as it governs the behavior and properties of substances under different conditions.