Question

If a liquid exerts a vapour pressure at a given temperature is it boiling?

Answer 1

Not unless the liquid vapour pressure is `1*atm`.

Explanation:

The `"normal boiling point"` is the temperature at which the vapour pressure of the solution is `1*atm`, and bubbles of vapour form directly in the liquid. Typically, we measure the normal boiling points of liquids, and thus we know at a given temperature that their vapour is `1*atm`. The magnitude of the boiling point is an excellent indicator of intermolecular force.

At lower pressures we can substantially reduce the boiling point, and this is the principle behind vaccuum distillation. Are you happy with this?