Colligative Properties and Vapor Pressure

A set of flashcards covering key concepts related to colligative properties, vapor pressure lowering, Raoult's law, and van't Hoff factors.

What are colligative properties?

Colligative properties are physical characteristics of a solution that depend on the number of particles dissolved, not the type of particle.

What are the four colligative properties discussed?

Vapor pressure lowering, freezing point depression, boiling point elevation, and osmotic pressure.

How does adding a non-volatile solute affect vapor pressure?

It reduces the amount of solvent molecules that can escape, leading to lower vapor pressure.

What does Raoult's law state?

The vapor pressure of a solution is directly proportional to the mole fraction of the solvent.

What is the theoretical van't Hoff factor (i)?

It is the ratio of moles of solute particles to moles of ionic formula units dissolved.

Why are measured van't Hoff factors generally less than theoretical values?

Due to ion pairing in solution.

What happens to the equilibrium of vapor pressure when a non-volatile solute is added?

Equilibrium is re-established with fewer vapor molecules, resulting in a lower vapor pressure.

How do volatile solutes and solvents affect total vapor pressure?

Both contribute to the overall vapor pressure of the solution.

What effect does ion pairing have on colligative properties?

It results in measured van't Hoff factors being less than theoretical values, which affecting calculations.

How can vapor pressure be calculated for a solution?

Using Raoult's law for both solvent and solute, while considering their respective mole fractions.