Question

What happens to the vapour pressure of a liquid when a non volatile solute is dissolved in it?

Answer 1

1. When a non-volatile solute is introduced to a liquid, the solution’s vapour pressure falls below that of the pure solvent.
2. This occurs because the solute molecules take up a portion of the solvent's surface area, limiting the amount of solvent molecules accessible for evaporation.
3. The rate of evaporation is thereby delayed, resulting in a lower vapour pressure.