Mixtures and chromatography

• Mixtures are Easily Separated-Not Like Compounds
• Mixtures

  • The parts of a mixture can be either elements or compounds, and they can be separated out by physical methods such as filtration, crystallisation, simple distillation, fractional distillation, and chromatography
• Mixtures

  • Air, which is a mixture of mainly nitrogen, oxygen, carbon dioxide and argon
  • Crude oil, which is a mixture of different length hydrocarbon molecules
• The properties of a mixture are just a mixture of the properties of the separate parts - the chemical properties of a substance aren't affected by it being part of a mixture
• Mixture of iron powder and sulfur powder

  • Will show the properties of both iron and sulfur - grey magnetic bits of iron and bright yellow bits of sulfur
• Paper Chromatography

  1. Draw a line near the bottom of a sheet of filter paper

  2. Add a spot of the ink to the line and place the sheet in a beaker of solvent

  3. The solvent moves up the paper, carrying the ink with it

  4. Each different dye in the ink will move up the paper at a different rate, separating out

  5. Dyes that are insoluble in the solvent will stay at the base

  6. When the solvent has nearly reached the top, take the paper out and leave it to dry

  7. The end result is a pattern of spots called a chromatogram
• You shouldn't use a pen to draw a line on the filter paper for paper chromatography