Mixtures
What is a mixture?
A mixture is an impure substance that can be separated into pure substance by physical means. eg. dirty water can be purified by filtration.
There are many different methods of separating mixtures. Each method relies on differences in the physical properties of the components of the mixture.
Methods of Physical Separation
| Method of separation |
Used to separate |
Basis - differences in | Example |
| Filtration | An insoluble solid from a liquid | Solubility | Muddy water |
| Decanting | An insoluble solid from a liquid | Solubility and density | Water and sand |
| Centrifuging | An insoluble solid from a liquid | Solubility and density | Blood cells from plasma |
| Evaporating | A soluble solid from a liquid | Boiling point | Salt from sea water |
| Distillation | A liquid from a soluble solid | Boiling point | Water from sea water |
| Fractional distillation |
Miscible liquids (liquids that can be mixed together as one) |
Boiling point | Alcohol from water |
| Separating funnel | Immiscible liquids (liquids that do not mix) | Density and miscibility | Oil and water |
| Paper chromatography | Soluble substances | Retention rates on paper | Food coloring |
| Crystallization | Soluble substances | Solublility | Different salts |