# Clausius-Clapeyron Equation

Written by Jerry Ratzlaff. Posted in Thermodynamics

Clausius-Clapeyron equation is the vapor pressure of given liquids or solids.

Abbreviated as $$p_s$$

## formula

$$In \left( \frac {p_2}{p_1} \right) = \frac {\Delta H}{R} \left( \frac {1}{T_1} \;-\; \frac {1}{T_2} \right)$$

Where:

$$p_1$$ = vapor pressure at the temperature

$$p_2$$ = vapor pressure at the temperature

$$\Delta H$$ = enthalpy of vaporization of the liquid

$$R$$ = real gas content

$$T_1$$ = temperature at which the vapor pressure is known

$$T_2$$ = temperature at which the vapor pressure is to be found