key term - Raoult’s law

Definition

Raoult's law states that the partial vapor pressure of a component in a solution is directly proportional to the mole fraction of that component in the solution. This principle applies to ideal solutions where intermolecular forces between different components are similar to those within each component.

5 Must Know Facts For Your Next Test

1. Raoult's law is mathematically expressed as $P_i = X_i P_i^0$, where $P_i$ is the partial vapor pressure, $X_i$ is the mole fraction, and $P_i^0$ is the pure component vapor pressure.
2. The law applies strictly to ideal solutions, which assume no change in enthalpy or volume upon mixing.
3. Non-ideal solutions exhibit deviations from Raoult’s Law due to differences in intermolecular forces.
4. Raoult’s Law helps explain colligative properties such as boiling point elevation and freezing point depression.
5. Henry's law can be used alongside Raoult’s law for dilute solutions where one component is volatile.

Review Questions

Related terms

Ideal Solution: A solution that follows Raoult's Law across all concentrations, with uniform intermolecular interactions.

Colligative Properties:

Properties of solutions that depend on the number of solute particles but not their identity, including boiling point elevation and freezing point depression.

Henry's Law:

States that the amount of gas dissolved in a liquid is proportional to its partial pressure above the liquid.