What is the difference between the boiling point elevation and the freezing point depression?

Answer 1

Vapor pressure is a measure of how easily something evaporates. Therefore, if something has a high vapor pressure, it's likely to have a low boiling point. If it has a low vapour pressure, it's likely to have a high boiling point.

For the same reason, if something has a high vapor pressure, it's likely to have a low freezing point, as some of it is still likely to be evaporating as a gas, rather than being a liquid at relatively cold temperatures, so it needs to be even colder to freeze as a solid.

Answer 2

Boiling point elevation is the raising of the temperature of a liquid's boiling point. Freezing point depression is lowering the freezing point of a liquid. These points can be changed by adding a solute (usually salts) to the pure solvent to create a solution. Equations to calculate change in temperature are (change in temp)freezing= i(van't Hoff factor) x Kf x m(molality) and (change in temp)boiling=i(van't Hoff factor) x Kb x m(molality) where Kf and Kb are constants.

Wikipedia has these both defined, and goes into further depth about both.

Answer 3

Boiling point elevation refers to the increase in the boiling point of a solvent when a solute is added, while freezing point depression is the decrease in the freezing point of a solvent due to the addition of a solute. Both phenomena are colligative properties that depend on the concentration of the solute particles, with boiling point elevation being directly proportional to that concentration, and freezing point depression being inversely proportional to it.