Free Science Lessons: Physical Separation Techniques

Overview

• Focus on physical separation techniques: Filtration and Crystallization.
• Used to separate mixtures, not elements in a compound.
• Separation of elements in compounds involves chemical reactions (e.g., reduction, electrolysis).

Filtration

• Purpose: To separate an insoluble solid from a liquid.
• Insoluble: Solid does not dissolve in the liquid.
• Example: Silver chloride (solid, s) and water (liquid, l).
  • Silver chloride is insoluble in water.
  • Uses state symbols to indicate physical state.
• Process:
  1. Use a filter funnel and filter paper.
  2. Pour the mixture into filter paper.
  3. Liquid passes through filter paper (called filtrate).
  4. Solid is trapped and separated.
• Application: Widely used in chemistry.

Crystallization

• Purpose: To separate a soluble solid from a liquid.
• Soluble: Solid dissolves in the liquid.
• Example: Sodium chloride (soluble) and water create an aqueous solution (aq).
  • Sodium chloride dissolves in water to form sodium chloride solution.
• Process:
  1. Leave solution to allow water to evaporate.
  2. Results in formation of solid sodium chloride crystals.
  3. State symbol changes from aq to s as sodium chloride becomes solid.
  4. Can speed up by gently heating (caution: some chemicals break down with heat).
• Considerations: Be mindful of heat as it can degrade some chemicals.

Additional Resources

• For further study and practice questions, refer to the vision workbook available via the provided link.