Clausius–Clapeyron relation


The Clausius–Clapeyron relation, named after Rudolf Clausius and Benoît Paul Émile Clapeyron, is a way of characterizing a discontinuous phase transition between two phases of matter of a single constituent. On a pressure–temperature (P–T) diagram, the line separating the two phases is known as the coexistence curve. The Clausius–Clapeyron relation gives the slope of the tangents to this curve.

Related formulas


dPslope of the tangent to the coexistence curve at any point, (N/m2)
dT temperature difference (K)
Llatent heat (joule/kg)
Ttemperature (K)
Δvspecific volume change of the phase transition (m3/kg)