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Sodium chloride is commonly known as table salt that we use in our daily lives. In its molten state it has a high boiling point because of the strong force of attraction between the positive and negative ions. In an aqueous solution, the boiling point is much lower because the ions are held in place by strong forces of attraction between water molecules and not by the force of electrostatic attraction. The question asks about raising the boiling point of a solution by adding a non volatile solute.
To raise the boiling point of a solution, its vapor pressure must increase above the surrounding atmospheric pressure. The vapor pressure of the solvent must also increase. This is accomplished by increasing the temperature of the solution.
A solution that contains a non-volatile solute has a lower vapor pressure than its pure solvent because the molecule of the solute is smaller and less dense. This causes the solution to require a higher temperature in order to reach its vapor pressure above the surrounding atmospheric pressure, which is the boiling point.
The concentration of the solute in the solution will determine how much its boiling point will change, which is measured by comparing the normal boiling point of the solvent to the boiling point at different concentrations of the solute. This is a property of a solution that can be derived from a graph. The following graph shows the normal boiling points of water (solvent) as a function of its molality in several solutions of sucrose and urea (non-volatile solutes). Notice that as the molality increases, the boiling point rises.