An Etymological Dictionary of Astronomy and Astrophysics
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An equation that relates the temperature and pressure dependence of phases in equilibrium with the heat interaction and volume change associated with a phase change: dP/dT = L/T ΔV, where dP/dT is the slope of the coexistence curve, L is the → latent heat, T is the temperature, and ΔV is the volume change of the phase transition.

Named after Émile Clapeyron (1799-1864), a French engineer and physicist, one of the founders of → thermodynamics; → equation.

An approximation of the → Clapeyron equation for liquid-vapor equilibrium that incorporates the → ideal gas law and states that the logarithm of vapor pressure is inversely proportional to temperature.

→ Clausius equation; → Clapeyron equation.