The Amazing World of Solutes, Solvents, and Solutions

Overview

A solution is a uniform mixture of a solute dissolved in a solvent. This chapter explains solutions, solubility, and the factors that affect how much solute can dissolve.

Key concepts

• A solution is a homogeneous mixture of solute and solvent.
• The solute is the substance that dissolves; the solvent dissolves it.
• A saturated solution cannot dissolve any more solute at a given temperature.
• Solubility usually increases with temperature for solids.
• Water is called the universal solvent.

Important terms / formulae

• Solute: substance that dissolves (e.g., sugar).
• Solvent: substance in which solute dissolves (e.g., water).
• Solubility: maximum solute that dissolves in a fixed solvent at a temperature.
• Saturated solution: a solution holding the maximum solute.

Solved example or key process

1. Add sugar to a glass of water and stir.
2. Keep adding until no more dissolves; this is a saturated solution.
3. Warm the water; the leftover sugar now dissolves.
4. This shows solubility increases with temperature.

Important questions

1. Define solute, solvent, and solution.
2. What is a saturated solution?
3. How does temperature affect the solubility of solids?
4. Why is water called the universal solvent?

Quick revision

A solution is a uniform mix of a solute in a solvent. Solubility is how much solute dissolves and usually rises with temperature for solids. A saturated solution holds the maximum solute at that temperature.