separating mixtures

• MIXTURES + COMPOUNDS:


  • Mixtures AND Compounds are both combinations of TWO or MORE SUBSTANCES.
  • COMPOUNDS are combinations of two or more substances that are CHEMICALLY COMBINED.
  • MIXTURES are combinations of two or more substances that are NOT CHEMICALLY COMBINED.
  • The substances in a mixture can be both ELEMENTS or COMPOUNDS, and they RETAIN their individual PROPERTIES.
  • Compounds can only be separated using CHEMICAL REACTIONS.
  • Mixtures can be separate using PHYSICAL METHODS.
• FILTRATION:


  FILTRATION is a method used to separate an INSOLUBLE SOLID from a liquid. This can be particularly useful for removing solid impurities from a reaction mixture or product.

  • Pour the mixture through FILTER PAPER, where the solid is trapped
  • liquid passes through filterpap.
• Evaporating + Crystallisation

  Dissolve soluble solids like salt in a solvent, recover by evaporation or crystallisation
• Evaporation


  • Pour solution into an evaporating dish and gently heat it
  • As solvent evaporates, solution becomes more concentrated and dry crystals form
  • Best used when substance does not decompose upon heating
• Crystallisation

  1. Pour solution in an evaporating dish

  2. Heat gently until crystals start to form, indicating solution has become saturated

  3. Allow solution to cool, causing formation of more crystals

  4. Filter out the crystals and leave them to dry in a warm place
• SIMPLE DISTILLATION:

  • SIMPLE DISTILLATION is a process to separate a LIQUID from a solution, often used when the liquids have different BOILING POINTS.
  • During distillation, the solution is heated to the temperature of the LOWEST BOILING POINT. This causes the component with the lower boiling point to EVAPORATE.
  • The vapour is then COOLED in a CONDENSER and collected as a liquid, leaving the component with the higher boiling point behind.
• Fractional distillation

  1. Use a fractionating column with glass rods, allows substances with different boiling points to separate effectively

  2. Creates a temperature gradient - high at bottom, low at top

  3. As vapour rises, temperature cools causing higher boiling point components to condense and fall back into flask

  4. Component with lowest boiling point rises and condenses into liquid, and collected in beaker

  5. Repeat process, raising temperature gradually to collect other liquids at different boiling points
• Fractional distillation is used when you have a mixture of more than two liquids that have different boiling points
• CHROMATOGRAPHY:


  • CHROMATOGRAPHY is a method used to separate and analyse the components of a mixture.
  • In paper chromatography, substances move at different rates, allowing them to be separated based on their solubility.
  • It can be used to separate out the DYES in an INK.
• How to Perform Paper Chromatography

  1. Draw a line near the bottom of the filter paper with a pencil, as pencil marks are INSOLUBLE

  2. Place a spot of the substance to be separated on the line

  3. Use a suitable SOLVENT, such as water or ethanol, depending on the substances

  4. Ensure the spot does not touch the solvent when you place the filter paper in the beaker

  5. The solvent will move up the paper, taking the substances with it

  6. Different substances in the mixture will travel at different speeds, resulting in separate spots

  7. Once the solvent has nearly reached the top, remove the paper and let it dry to see the CHROMATOGRAM