Filtration and Crystallisation

• What are physical separation techniques used for?

  To separate mixtures.
• What is the limitation of physical separation techniques?

  • Cannot separate elements in a compound
  • Only separate mixtures
• What is filtration used for?

  To separate an insoluble solid from a liquid.
• What does the term 'insoluble' mean?

  It means that the solid will not dissolve in the liquid.
• What is the state symbol for a solid?

  S.
• What is the state symbol for a liquid?

  L.
• How does filtration work?

  The liquid passes through the filter paper while the solid is trapped.
• What is crystallization used for?

  • To separate a soluble solid from a liquid
  • Forms crystals as the liquid evaporates
• What happens to sodium chloride when mixed with water?

  It dissolves to form an aqueous solution.
• What does the state symbol AQ represent?

  It indicates that a substance is dissolved in water (aqueous solution).
• How can sodium chloride be separated from water?

  By evaporating the water to leave solid sodium chloride crystals.
• What happens to the state symbol of sodium chloride after crystallization?

  It changes from AQ to S, indicating it is now a solid.
• What are the steps involved in crystallization?

  1. Dissolve sodium chloride in water to form a solution
  2. Allow water to evaporate
  3. Collect solid sodium chloride crystals
• Why might gentle heating be used in crystallization?

  To speed up evaporation while preventing chemical breakdown.