Reactions of metals

• Reactivity series

  • The more reactive a metal is the more vigorous its reactions
  • The more easily it loses electrons to make positive ions
• Oxidation and reduction-REDOX REACTIONS

  • Oxidation=metal gaining oxygen
  • Reduction=metal loses oxygen
  • Oxidation=loss of electrons
  • Reduction=gain of electrons
• Using carbon to extract metals

  • Unreactive metals are found as the metals alone
  • Metals below carbon in the reactivity series are extracted from their oxides by reduction with carbon
• Extracting aluminium

  • Metals above carbon in the reactivity series are extracted via electrolysis
  • Electrolysis is expensive because large amounts of energy are required to:
  • Melt compounds
  • Produce the electrical current
• Process

  1. The electrolyte is aluminium dioxide dissolved in molten cryolite
  2. Aluminium is produced at the graphite cathode
  3. Oxygen is produced at the graphite anode and reacts to make carbon dioxide