Crystallisation - GCSE Chemistry Definition

Crystallisation is a separation technique used in chemistry to purify substances. It involves dissolving a solid in a liquid, such as water, to create a solution. The solution is then cooled or allowed to evaporate slowly, so the dissolved substance forms solid crystals. These crystals are usually pure and can be separated from the remaining liquid, called the mother liquor.

This process takes advantage of how different substances dissolve at different temperatures and helps students understand how pure chemicals can be obtained from a mixture. Crystallisation is often used to make things like table salt and sugar pure enough to use.