CBSE Class 12 Chemistry – Solutions

Chapter Overview

This chapter focuses on the study of solutions, particularly liquid solutions and their properties. It explains types of solutions, various ways to express their concentration, the nature of solutes and solvents, and how temperature and pressure affect solubility. The chapter also delves into Raoult’s law, ideal and non-ideal solutions, and important colligative properties such as relative lowering of vapor pressure, elevation in boiling point, depression in freezing point, and osmotic pressure. It includes the van't Hoff factor to account for abnormal colligative behavior due to solute association or dissociation.

Important Keywords

• Solution: A homogeneous mixture of two or more substances.
• Solute: The substance that is dissolved in a solvent.
• Solvent: The component present in larger quantity in a solution.
• Molality (m): Moles of solute per kilogram of solvent.
• Molarity (M): Moles of solute per liter of solution.
• Raoult’s Law: The partial vapor pressure of each volatile component in a solution is proportional to its mole fraction.
• Ideal Solution: Obeys Raoult’s law over the entire concentration range.
• Non-Ideal Solution: Deviates from Raoult’s law showing positive or negative deviation.
• Colligative Properties: Properties that depend on the number of solute particles, not their identity.
• van’t Hoff Factor (i): Correction factor used for calculating colligative properties in case of association or dissociation of solute particles.