How does adding a solute to a solvent affect the boiling point of the solvent?

1 Answer
Jul 29, 2017

It usually increases the #"boiling point of the solution"# with respect to the #"boiling point of the solvent..........."#

Explanation:

This is an example of a so-called #"colligative property"#, a property that depends on the NUMBER of particles that you dissolve in the solvent. When we dissolve a non-ionic solute in a solvent, the boiling point of the solvent INCREASES by an amount proportional to the mole fraction of the solute.

And likewise, the freezing point of the solution DECREASES by an amount proportional to the mole fraction of the solute. And this is the reason in cold weather, sometimes you see grit salt spread on the roads and footpaths to melt icy patches.

Given accurate masses of solute, and accurate determinations of so-called #"freezing point depression"# and #"boiling point elevation"#, the molecular mass of the solute may sometimes be determined.

Note that if ionic solutes are used, the solute is conceived to break up into its constituent ions, and multiply the colligative effect.