Clausius–Clapeyron relation is a way to characterize a discontinuous phase transition happens between two phase of a single constituent. The relation is named after Rudolf Clausius and Benoît Paul Émile Clapeyron. Use our online Clausius Clapeyron relation calculator to find the slope of the tangent by providing the entropy (S1), entropy (S2), volume (V1) and volume (V2).