Mixtures
* Definition: A mixture is a combination of two or more substances that are physically mixed but not chemically bonded.
* Components: The components of a mixture retain their individual chemical properties.
* Separation: The components of a mixture can usually be separated by physical means (like filtration, evaporation, magnetism, etc.).
* Examples: Salt and pepper, sand and water, air (a mixture of gases)
Pure Substances
* Definition: A pure substance has a fixed chemical composition and uniform properties throughout.
* Components: A pure substance consists of only one type of molecule.
* Separation: The components of a pure substance cannot be separated by physical means; they require chemical reactions.
* Examples: Water (H₂O), gold (Au), sugar (C₁₂H₂₂O₁₁)
Key Differences:
* Composition: Mixtures have variable composition, while pure substances have fixed composition.
* Properties: Components in a mixture retain their original properties, while components in a pure substance lose their individual properties and form a new substance with unique properties.
* Separation: Mixtures can be separated by physical means, while pure substances can only be separated by chemical means.
In Summary:
Think of a mixture as a salad – you can easily pick out the different vegetables. A pure substance is like a cake – all the ingredients are combined into one new, uniform entity.
