<P> If the heat of vaporization and the vapor pressure of a liquid at a certain temperature are known, the boiling point can be calculated by using the Clausius--Clapeyron equation, thus: </P> <Dl> <Dd> T B = (1 T 0 − R ln ⁡ P P 0 Δ H vap) − 1, (\ displaystyle T_ (\ text (B)) = (\ Bigg () (\ frac (1) (T_ (0))) - (\ frac (R \, \ ln (\ frac (P) (P_ (0)))) (\ Delta H_ (\ text (vap)))) (\ Bigg)) ^ (- 1),) </Dd> </Dl> <Dd> T B = (1 T 0 − R ln ⁡ P P 0 Δ H vap) − 1, (\ displaystyle T_ (\ text (B)) = (\ Bigg () (\ frac (1) (T_ (0))) - (\ frac (R \, \ ln (\ frac (P) (P_ (0)))) (\ Delta H_ (\ text (vap)))) (\ Bigg)) ^ (- 1),) </Dd> <Dl> <Dd> T B (\ displaystyle T_ (B)) is the boiling point at the pressure of interest, </Dd> <Dd> R (\ displaystyle R) is the ideal gas constant, </Dd> <Dd> P (\ displaystyle P) is the vapour pressure of the liquid at the pressure of interest, </Dd> <Dd> P 0 (\ displaystyle P_ (0)) is some pressure where the corresponding T 0 (\ displaystyle T_ (0)) is known (usually data available at 1 atm or 100 kPa), </Dd> <Dd> Δ H vap (\ displaystyle \ Delta H_ (\ text (vap))) is the heat of vaporization of the liquid, </Dd> <Dd> T 0 (\ displaystyle T_ (0)) is the boiling temperature, </Dd> <Dd> ln (\ displaystyle \ ln) is the natural logarithm . </Dd> </Dl>

A substance has a melting point of 0 and a boiling point of 100