# How do you calculate boiling point change?

Jun 4, 2018

We normally quote the $\text{normal boiling point}$, the which specifies an ambient pressure of $1 \cdot a t m$. And the $\text{boiling point}$ is that CONDITION of temperature where the VAPOUR PRESSURE of the liquid is equal to the ambient pressure, and bubbles of vapour form directly in the liquid.
And this definition underlies $\text{vacuum distillation}$ where the PRESSURE is reduced so that an otherwise involatile liquid (i.e. involatile at $1 \cdot a t m$), has a reduced boiling point at the lower pressure.