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Separating mixtures

Separating mixtures into pure substances.

 

There are a variety of techniques that can be used to separate mixtures into pure substances. Eaxh method uses differences in the physical properties of the materials in the mixture to achieve separation.

 

 Method of separation  Used to separate ...
 Filtration an insoluble solid from a liquid based upon differences in size. eg. clay from water
 Evaporation a soluble solid from a liquid based upon differences in boiling points. eg. salt from sea water
 Crystallisation two or more soluble solids from one another based upon differences in solubilities
 Distillation a solvent from a soluble soild based upon differences in boiling point. eg. water from sea water
 Fractional distillation miscible liquids from one another based upon differences in boiling point. eg. water and ethanol (alcohol)
 Separating funnel

immiscible liquids from one another based upon differences in miscibility. eg. oil and water.

 Magnetism solids from one another based upon differences in their ferromagnetic properties. eg. aluminum and iron.
 Paper chromatography soluble substances from one another based upon differences in retention rates as a solvent moves over paper.
 Decanting an insoluble solid from a liquid by carefully pouring off the liquid. Based upon differences in density.

 

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