Clausius-Clapeyron Calculator
Calculate vapor pressure, temperature, or enthalpy of vaporization using the Clausius-Clapeyron equation.
Clausius-Clapeyron Equation
Solve For:
= 100.00 °C
= 85.00 °C
Final Pressure (P2)
0.577268 atm
Clausius-Clapeyron Equation:
ln(P2/P1) = -(Delta Hvap/R) * (1/T2 - 1/T1)
ln(P2/P1):
-0.549449
Understanding the Clausius-Clapeyron Equation
The Clausius-Clapeyron equation describes how vapor pressure changes with temperature during a phase transition. It is derived from thermodynamic principles and assumes that the enthalpy of vaporization is constant over the temperature range. The equation is essential for predicting boiling points at different pressures and for understanding phase equilibria.
Common Enthalpies of Vaporization
| Substance | Delta Hvap (kJ/mol) | Boiling Point (°C) |
|---|---|---|
| Water | 40.7 | 100 |
| Ethanol | 38.6 | 78.4 |
| Acetone | 30.7 | 56.1 |
| Benzene | 30.8 | 80.1 |
| Ammonia | 23.3 | -33.4 |
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Editorial Note
MyCalcBuddy Editorial Team
This page is maintained as an educational calculator reference.
Formula Source: Chemistry: The Central Science
by Brown, LeMay, Bursten