mixtures

• what is a mixture?

  a mixture consists of two or more elements or compounds not chemically combined together
• do the properties of substances in a mixture change?

  no
• what are the methods mixtures can be separated through?

  • filtration
  • crystallisation
  • simple distillation
  • fractional distillation
  • chromatography
• describe filtration (used to separate an insoluble solid from a liquid)

  1. pour mixture into the filter paper
  2. filtrate passes through paper

  
• describe crystallisation (used to separate a soluble solid from a liquid)

  1. leave the solution for a few days for the liquid to evaporate
  2. OR gently heat the solution to evaporate liquid (some chemicals can break down w heat tho)

  
• describe simple distillation (used to separate a soluble solid and liquid but keep the liquid)

  1. place mixture into the distillation flask
  2. heat mixture using a bunsen burner
  3. vapour passes into condensor where it is cooled
  4. collect liquid in flask

  
• describe fractional distillation (used to separate a mixture of liquids at diff boiling points )

  1. gently heat mixture
  2. chemical with lower boiling point will go up fractionating column faster than higher boiling point
  3. the vapours will pass through the condensor separately where they can be collected in the beaker

  
• describe chromatography (used to separate substances in a mixture)

  1. put dots of the colours on the chromatography paper
  2. place bottom of the paper into a solvent
  3. solvent moves up paper and mixture separates