Determining Purity Using Melting and Boiling Points

Key Concepts

• Pure Substance: A pure substance can be a single element (e.g., pure silicon) or a single compound (e.g., pure sodium chloride).
  • It is not mixed with any other substances.

Determining Purity

• Melting and Boiling Points:
  • Pure substances have specific, fixed melting and boiling points.
  • Impure substances melt and boil over a range of temperatures.
• Experiment Example:
  • Pure water:
    • Fixed melting point at 0°C.
    • Fixed boiling point at 100°C.
  • Impure water:
    • Melts and boils over a range of temperatures.

Formulations

• Definition: A formulation is a complex mixture designed as a useful product.
  • The quantity of each component is carefully measured.
  • Formulations are tailored to have specific properties.

Additional Resources

• Revision workbooks and questions are available to practice topics on pure and impure substances and formulations.

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