Mixtures

• What is a pure substance?

  Only one element or compound
• What defines a mixture?

  Two or more different substances, not chemically joined together
• What is the process of filtration used for?

  • Separates insoluble solid from a liquid
  • Example: sand and water
• Describe the steps involved in the filtration process.

  1. One beaker contains a mixture of sand and water, the other contains a funnel with filter paper.
  2. The solid and liquid mixture is poured into the filter funnel.
  3. The water drips through the filter paper, while the solid particles are caught in it.
• What is crystallization used for?

  • Produces solid crystals from a solution
  • Example: copper sulfate crystals
• Outline the steps of the crystallization process.

  1. A solution is placed in an evaporation basin and heated with a Bunsen burner.
  2. The volume of the solution decreases as some water evaporates, and solid particles begin to form.
  3. All the water evaporates, leaving solid crystals behind.
• What is distillation used for?

  • Separates a solvent from a solute
  • Example: pure water from seawater
• Describe the steps involved in the distillation process.

  1. Salty water is heated.
  2. The water vapor cools in the condenser and drips into a beaker.
  3. The water has condensed and is now in the beaker, while the salt stays behind.
• What is paper chromatography used for?

  • Separates mixtures of soluble substances
  • Example: plant dye
• Outline the steps of the paper chromatography process.


  1. Ink is dotted along a pencil line on paper.
  2. As the paper is lowered into the solvent, some dye spreads up the paper.
  3. The paper absorbs the solvent, and the dye spreads further up the paper.
• What are the two phases in paper chromatography?

  Stationary phase and mobile phase
• How can you tell if a substance is pure or a mixture using chromatography?

  By observing the number of spots on the paper