Vapour Pressure Calculator

Calculate the vapour pressure at a different temperature using the Clausius-Clapeyron equation:
\[ \ln\left(\frac{P_2}{P_1}\right) = -\frac{\Delta H_{vap}}{R}\left(\frac{1}{T_2} – \frac{1}{T_1}\right) \]

* Enter the reference vapour pressure \( P_1 \), reference temperature \( T_1 \) (K), enthalpy of vaporization \( \Delta H_{vap} \) (J/mol), and the new temperature \( T_2 \) (K).

Step 1: Enter Reference Data

Reference Vapour Pressure, \( P_1 \) (in desired units):

Example: 1 (e.g., 1 atm, if using atm units)

Reference Temperature, \( T_1 \) (K):

Example: 298 K

Enthalpy of Vaporization, \( \Delta H_{vap} \) (J/mol):

Example: 40000 J/mol

New Temperature, \( T_2 \) (K):

Example: 310 K

Step 1: Enter Reference Data

Calculated Vapour Pressure at T₂