hen adding a solute to water, the vapor pressure will and the boiling point will .

When a solute is added to water, the vapor pressure will decrease and the boiling point will increase.

Explanation:

When a solute is added to water, a solvent's vapor pressure will decrease because of the displacement of solvent molecules by the solute. i.e. some of the solvent molecules at the surface of the water are replaced by the solute.When a solute is added to water, a solvent's boiling point will increase because water molecules need more energy to produce required pressure to escape the boundary of the liquid , so as the number of particles increase in the liquid it increase the boiling point.