Separation Techniques

• Chromatography


  A method used to separate mixtures that are soluble in the same solvent
• Chromatography


  1. Mixture like ink is placed on paper

  2. Solvent moves up paper

  3. Separates constituents of ink

  4. Produces chromatogram
• Evaporation


  A method to separate a solute and a solvent, keeping the solute
• Evaporation


  1. Solution is heated

  2. Left in evaporating basin

  3. Solvent evaporates

  4. Solute left behind as solid
• Key terms


  • chromatography
  • chromatogram
  • compound
  • condenser
  • dissolve
  • distillation
  • evaporation
  • filtrate
  • filtration
  • filter paper
  • impure substance
  • insoluble
  • mixture
  • pure substance
  • residue
  • saturated
  • separate
  • solvent
  • solute
  • soluble
  • solubility
  • solution
• Filtration


  A method to separate a mixture of an undissolved solid and a liquid
• Filtration


  1. Filter paper has small holes

  2. Particles in liquid/solution fit through holes

  3. Larger solid particles held back by paper
• Residue


  Solids left behind in the filter paper
• Filtrate


  The liquid that passes through the filter paper
• Distillation


  A method that separates a solute and a solvent while keeping the solvent
• Distillation


  1. Solution boiled, solvent turns to gas

  2. Gas cooled in condenser, turns back to liquid and collected
• Mixture


  Different substances found together, but not chemically bonded
• In a compound, different substances are chemically bonded together, while in a mixture they are not
• The substances that make up a mixture keep their own properties and are easy to separate
• You can change the amounts of the substances in a mixture
• You can tell the difference between a pure substance and an impure substance - a pure substance has a single, sharp melting point, while an impure substance (a mixture) has a range of temperatures for its melting point
• Solution


  A type of mixture made of two parts: solvent (the liquid that makes up most of the solution) and solute (the substance that is added to the solvent and dissolves into it)
• The solute usually starts as a solid, and its particles break away from each other and move into the solvent
• Solubility


  The solubility of a solute means how much solute can dissolve in a certain volume of solvent
• Different solutes have different solubilities in different solvents
• Increasing the temperature often increases the solubility
• Soluble substances can dissolve, insoluble substances cannot
• Saturated


  When so much solute has been added to the solvent that no more can dissolve, we say the mixture is saturated