How To Separate Solutions, Mixtures & Emulsions

Learn the basics about separating solutions, mixtures and emulsions when learning about separation techniques as a part of chemical tests. A solution is a mixture of two or more substances in the same phase. It is formed when a solute dissolves in a solvent. When salt is dissolved in water, a solution is formed. A solution can also be formed when two or more miscible liquids are mixed together. To separate dissolved salt from water, evaporate as much water as possible, leaving behind white salt crystals.This separation technique is known as evaporation. To separate ethanol from water, use the fact that both substances have very different boiling points. This mixture can be separated by simple distillation. The lower boiling component will boil and evaporate first, so it can easily be collected separately from the ethanol. Salt and water, and ethanol and water are homogenous mixtures – this means that the components of the mixture are in the same phase, or the composition of the mixture is uniform throughout. Heterogeneous mixtures are where the components in the mixture are not in the same phase, or the composition of the mixture is uneven. A mixture of sulfur and iron filings is a heterogenous mixture. There are many different techniques to separate mixtures, depending on whether the mixture is homogenous or heterogeneous. Magnets can be used to separate out magnetic components in heterogenous mixtures. Salt and sand can be separated using water to dissolve the salt, and then evaporation to separate the salt back from the water once more. Two immiscible liquids, such as oil and water, can be separated using a separatory funnel.