Chemistry 1 separating substances

• Properties of solids


  • Fixed volume
  • Cannot be compressed
  • Fixed shape
  • Cannot be easily changed
  • Ideal for building large structures
  • Do not flow
  • Cannot be poured
  • High density
• Properties of liquids


  • Cannot be compressed
  • Fixed volume
  • Can flow easily
  • No fixed shape
  • Take the shape of the container
  • Usually have lower density than solids
• Properties of gases


  • Easy to compress
  • No fixed volume
  • No fixed shape
  • Spread out and fill any container
  • Less dense than liquids
• Solution


  • Made from a solute (a solid) and a solvent (a liquid)
  • Liquid is always clear (transparent), but may be coloured
• Soluble solids


  Solids that dissolve in water to make a solution
• Insoluble solids


  Solids that do not dissolve in water, making the water go cloudy
• Solubility


  • The ability of a solute to dissolve in a solvent
  • Some solutes like sugar are very soluble, others like salt are less soluble
  • Eventually no more solute will dissolve, solution is saturated
  • Solubility is defined as how much solute will dissolve in 100g of water
• Melting


  Solid -> Liquid
• Freezing


  Liquid -> Solid
• Evaporation


  Liquid -> Gas
• Condensing


  Gas -> Liquid
• Sublimation


  Solid <-> Gas
• How to get salt from salty water - evaporation or crystallisation
• Separating a solute from a solution

  1. Heat the solution to evaporate the solvent

  2. Let the remaining solution sit to allow the solute to crystallise
• Boiling points: Water - 100 degrees Celsius, Salt (sodium chloride) - 1465 degrees Celsius
• Simple distillation


  1. Heat the solution until it reaches boiling point

  2. Evaporated water turns into steam and travels to the liebig condenser

  3. Liebig condenser cools the steam, causing it to condense into pure water

  4. Salt does not evaporate and stays behind
• Paper chromatography


  1. Ink dissolves in water on paper and solvent

  2. Coloured substances with different solubilities travel different distances through the paper
• Filtration


  • Can separate a solid which does not dissolve (like sand) from a liquid (like water)
  • Cannot separate a dissolved solid (like salt) from water