Colligative Properties Quiz: Test Your Knowledge of Solutions

What is the term used to describe solutes that do not have a significant vapour pressure?

Which law describes the relationship between the vapour pressure of a solution and the mole fraction of the solvent particles?

What is the reason behind the boiling point elevation in a solution with a nonvolatile solute?

The change in boiling point temperature of a solution is dependent on which of the following factors?

In the context of boiling point elevation, what must be done after calculating the change in boiling point temperature?

What are colligative properties?

What is the mole fraction of a component in a solution?

Why is mole fraction considered a useful concentration unit?

How can the mole fraction of one substance be calculated if there are only two substances in a mixture?

What does the term 'colligative' mean in the context of colligative properties?

Properties of Solutions

Properties of solutions are similar to those of their respective pure solvents, as the majority of the solution is the solvent.
However, some properties of solutions differ from pure solvents in measurable and predictable ways, proportional to the fraction of solute particles.

Colligative Properties

Colligative properties are related to the number of solute particles, not their identities.
These properties are a result of the solute particles occupying space in the solution.

Mole Fraction

Mole fraction (χ) is the number of moles of a component divided by the total number of moles in the sample.
Mole fraction is always a number between 0 and 1, with no units.
The sum of the mole fractions of all substances in a mixture equals 1.

Vapour Pressure Depression

Solutions have a lower vapour pressure than pure solvents, dependent on the fraction of solute particles.
This is known as vapour pressure depression or lowering.
Vapour pressure of the solution can be calculated using Raoult's law: Psoln = χsolv * P*solv.

Boiling Point Elevation

The normal boiling point of a solution is higher than that of the pure solvent.
This is due to the depressed vapour pressure of the solution.
The change in boiling point (ΔTb) can be calculated using: ΔTb = m * Kb.
Kb is the boiling point elevation constant, characteristic of the solvent.
The boiling point of the solution is calculated by adding the change in boiling point temperature to the boiling point of the pure solvent.

Learn about colligative properties of solutions which differ from pure solvents in measurable and predictable ways. These properties are proportional to the fraction that the solute particles occupy in the solution.