Mixtures and Dissolving

Mixtures

A mixture is made up of two or more substances that are not chemically bonded together, so the substances can be easily separated from each other. In a mixture, each substance retains its own properties. An example of a mixture is sand in water.

Water and sand are not joined together so we can separate the mixture through filtering, into water and sand. This is because they are two separate substances.

What is a Solution?

A solution is a type of mixture where one substance is dissolved in another.

The salt particles dissolve in the water in an even distribution.

Dissolving

Mixtures can be made in many ways, one way is through dissolving.

An example of dissolving is when salt is stirred into water, the salt dissolves in the water.

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In this example, the salt is the solute and the water is the solvent.

Remember:

  • The substance that dissolves is the solute
  • The substance that the solute dissolves in is called the solvent

Which means that in a salt solution, salt is the solute and the water is the solvent. The solute and solvent are mixed completely.

The techniques to separate the contents of mixtures are filtration, evaporation, distillation and chromatography.

Comparing Properties of Mixtures and Compounds

Mixtures Compounds
Definition A mixture is a combination of two or more substances that are not chemically bonded together A compound contains atoms of different elements that are chemically bonded together in a fixed ratio
Chemically joined or not The substances it contains are not chemically joined together The elements it contains are chemically joined together
Ability to separate Can easily separate each substance from a mixture Can only separate each element in a compound using chemical reactions
Properties Each substance in the mixture keeps its own properties Each element in the compound has different properties to the compound formed
Composition Mixtures contain different elements and compounds – The amount of each substance in a mixture can be varied Compounds contain different elements in a fixed ratio – The amount of each element in a compound can not be varied, they are chemically combined
Examples Salt water, air, soda, ethanol in water Water, carbon dioxide, salt