Mixtures

• Mixtures

  Two or more elements or compounds not chemically combined together.
• Can be separated via physical processes:

  -Filteration

  -Crystallisation

  -Simple Distillation

  -Fractional Distillation 

  -Chromotography
• Filtration

  used to separate an insoluble solid from a liquid

  Method:

  1.One beaker contains a mixture of solid and liquid, the other contains a funnel with filter paper

  2.The solid and liquid mixture is poured into the filter funnel

  3.The liquid drips through the filter paper but the solid particles are caught in the filter paper
• Crystallisation

  used to produce solid crystals from a solution

  Method:

  1.A solution is placed in an evaporating basin and heated with a Bunsen burner.

  2.The volume of the solution has decreased because some of the water has evaporated. Solid particles begin to form in the basin.

  3.All the water has evaporated, leaving solid crystals behind.
• Simple Distillation

  used to separate a solvent from a solution

  Method:

  1.Salty water is heated

  2.The water vapour cools in the condenser and drips into a beaker

  3.The water has condensed and is now in the beaker, the salt stays behind
• Fractional Distillation

  used to separate different liquids from a mixture of liquids

  Method:

  When the mixture is heated:

  -vapours rise through a column which is hot at the bottom, and cooler at the top

  -vapours condense when they reach a part of the column that is below the temperature of their boiling point

  -each liquid is led away from the column
• Chromatography

  used to separate mixtures of soluble substances.

  Method:

  1.Ink or plant dye is dotted along the pencil line.

  2.As the paper is lowered into the solvent, some of the dye spreads up the paper

  3.The paper has absorbed the solvent, and the dye has spread further up the paper