Answer to Question #178806 in General Chemistry for Duarte

Question

I have the following graph:

https://i.ibb.co/MgD2ZG7/image.png

with the following expression for the chemical potential variation:

$u_1(l)=u_1^*(l)+RTlnx_1$

How do I explain why the boiling point of the aqueous solution of a non-volatile solute increases?

Answer 1

Boiling-point elevation describes the phenomenon that the boiling point of a liquid (a solvent) will be higher when another compound is added, meaning that a solution has a higher boiling point than a pure solvent. This happens whenever a non-volatile solute, such as a salt, is added to a pure solvent, such as water. The boiling point can be measured accurately using an ebullioscope.

In the graph boiling point is at T_b and T_{b' '}