Mixtures and Separation Techniques

This lesson covers mixtures and the key separation techniques required by AQA GCSE Combined Science Trilogy (8464, Chemistry 4.1.1). A mixture consists of two or more substances that are not chemically bonded together. Because the substances retain their individual properties, they can be separated by physical methods.

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What Is a Mixture?

A mixture contains two or more substances that are not chemically combined. The components of a mixture:

• Retain their individual properties (unlike compounds).
• Can be separated by physical methods — no chemical reactions are needed.
• Can be present in any proportion — there is no fixed ratio.

Examples of mixtures include air (a mixture of gases), sea water (salt dissolved in water) and rock (a mixture of different minerals).

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Separation Techniques Decision Tree