Daily answer writing · Thu, 22 Oct, 2026
Derive the Clausius–Clapeyron equation; boiling point of water at 0.5 atm
Starting from the Clapeyron equation, derive the Clausius–Clapeyron equation for liquid–vapour equilibrium, stating the assumptions made. Use it to estimate the boiling point of water at 0.5 atm ($\Delta_{vap}H = 40.7\ \text{kJ mol}^{-1}$, normal boiling point 373.15 K).
Syllabus: Common to CSE Paper I, IFoS Paper I and Geo-Scientist Mains (physical): phase equilibria, Clapeyron and Clausius–Clapeyron equations.
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