Chapter 14.4, Problem 50SSC

Interpretation Introduction

Interpretation:

The reason for solution to have higher boiling point than pure solvent needs to be explained.

Concept introduction:

Vapor pressure: It is the pressure which is exerted by a liquid particle entering the vapor state in a closed container.

Boiling Point: The boiling point is defined as temperature when the vapor pressure of a liquid becomes equal to the atmospheric pressure or external pressure.

Answer to Problem 50SSC

On addition of a solute to a solvent, the vapor pressure of the resulting solution decreases. The boiling point of a solution is associated with the vapor pressure of the solution. So, the boiling point of the solution will increase as higher temperature is required for vapor pressure of the solution to be equal to the external pressure. That is why the boiling point of a solution is higher than pure solvent.

Explanation of Solution

Solution consists of two components- solute and solvent, so in a solution, solvent contains a solute, so lesser solvent particles occupy the surface and lesser particles escape into the gaseous state that’s why vapor pressure of solution is lower than pure solvent.

When a solute is added to a solvent, the vapor pressure of the resulting solution decreases. The boiling point of a solution is associated with the vapour pressure of the solution. So, the boiling point of the solutionwill increase as higher temperature is required for vapor pressure of the solution to become equal to the external pressure.