What effect does a nonvolatile solute have on the boiling point of a solution?

A nonvolatile solute elevates the boiling point of a solution due to a phenomenon known as boiling point elevation, which is a colligative property. Colligative properties depend on the number of solute particles in a solution rather than the identity of those particles.

When a nonvolatile solute is dissolved in a solvent, it disrupts the solvent's ability to vaporize. This means that more energy (in the form of heat) is required for the solvent to transition from the liquid phase to the vapor phase, effectively raising the temperature at which the solution boils. The extent of this boiling point elevation can be quantitatively described using the equation:

ΔT_b = i * K_b * m

In this equation, ΔT_b represents the change in boiling point, i is the van 't Hoff factor (which accounts for the number of particles the solute dissociates into), K_b is the ebullioscopic constant of the solvent, and m is the molality of the solution.

Thus, when a nonvolatile solute is added, it elevates the boiling point of the solution compared to the pure solvent. This principle is significant in many practical applications, including cooking and industrial processes.