Filtration and crystallisation

• What are some methods used to separate mixtures?

  Filtration, crystallisation, simple distillation, fractional distillation, and chromatography
• What factors determine the method chosen to separate mixtures?

  • The type of mixture
  • The physical properties of the components
• What is the purpose of filtration?

  To separate an insoluble solid from a liquid
• How does filtration work?

  It uses a physical barrier, such as filter paper, to separate particles based on size
• What is an example of an insoluble solid?

  Sand
• What happens to the filter paper during filtration?

  It allows small molecules and dissolved ions to pass through while trapping larger particles
• Describe the process of filtration step by step.

  1. Prepare a filter funnel with filter paper.
  2. Pour the solid-liquid mixture into the funnel.
  3. The liquid passes through the filter paper.
  4. The solid particles are retained on the filter paper.
• What is crystallisation used for?

  To produce solid crystals from a solution
• How does crystallisation occur?

  By evaporating the solvent from a solution
• What is an example of a substance obtained through crystallisation?

  Copper sulfate crystals
• Outline the steps to obtain large, regularly shaped crystals through crystallisation.

  1. Place the solution in an evaporating basin.
  2. Warm the solution over a boiling water bath.
  3. Stop heating when crystals form around the edge.
  4. Cool the remaining solution and pour away excess liquid.
  5. Dry the crystals using a warm oven or filter paper.
• What is the role of the solvent in crystallisation?

  It dissolves the solute to form a solution
• What happens to the solution during the crystallisation process?

  The volume decreases as the solvent evaporates
• What is the result of the crystallisation process?

  Solid crystals are left behind after evaporation
• What is the difference between filtration and crystallisation?

  • Filtration separates insoluble solids from liquids.
  • Crystallisation produces solid crystals from a solution by evaporating the solvent.