# What is the enthalpy of vaporization for a compound that has a vapor pressure of #"135 torr"# at #52^@ "C"# and #"24.3 torr"# at #0^@ "C"#?

##### 1 Answer

Your compound's enthalpy of vaporization will be close to **24.3 kJ/mol**.

To determine the enthalpy of vaporization, **Clausius-Clapeyron equation**. There are several equivalent forms in which you can write this equation, so I'll just use the one I remember

**273 K** and **325 K**, respectively;

So, plug in your values into the above equation and solve for

Rounded to three sig figs and expressed in kJ, the answer will be

Note that this is only an estimate, under the assumption that in the pressure and temperature range examined, the enthalpy of vaporization is essentially linear, but that is not always the case.

(3rd paragraph here)

http://en.wikipedia.org/wiki/Enthalpy_of_vaporization