Electrolysis - Aluminium Oxide

• What is the cheap and easy way to reduce metal oxides?

  Reduction with carbon
• What is the melting point of aluminium oxide?

  Over 2000 degrees Celsius
• What happens to oxygen ions at the anode during electrolysis?

  They lose electrons and are discharged as oxygen atoms
• Why can't aluminium oxide be used directly for electrolysis?

  Because it is solid and the ions are fixed in place
• What is the definition of electrolysis?

  A process that separates ionic compounds into pure elements using electric current
• What mineral is mixed with aluminium oxide to lower its melting point?

  Cryolite
• What is the overall equation for the electrolysis of aluminium oxide?

  Aluminium oxide (liquid) → Aluminium (liquid) + Oxygen (gas)
• What equipment is needed for the electrolysis of molten aluminium oxide?

  A beaker, two carbon electrodes, and a power source
• What are the characteristics of the ions in molten aluminium oxide during electrolysis?

  • Oxygen ions: O^2- (negative)
  • Aluminium ions: Al³⁺ (positive)
• What is the role of cryolite in the electrolysis of aluminium oxide?

  • Lowers the melting point of aluminium oxide
  • Reduces energy requirements for melting
• What process is used to extract reactive metals from their oxides?

  Electrolysis
• What is the significance of the melting point of aluminium oxide in the electrolysis process?

  • High melting point (>2000°C) requires energy-intensive melting
  • Must be molten for ions to move freely
• What must be done to aluminium oxide before electrolysis can occur?

  It must be melted into a molten state
• What do the positive ions in the electrolyte do at the cathode?

  They gain electrons to form aluminium atoms
• What is the half equation for the reaction at the anode?

  Oxygen ions form oxygen atoms plus electrons
• What are the steps involved in the electrolysis of aluminium oxide?

  1. Purify aluminium oxide from bauxite
  2. Mix with cryolite to lower melting point
  3. Melt the mixture to create molten aluminium oxide
  4. Set up electrolysis equipment with electrodes and power source
  5. Conduct electrolysis to produce aluminium and oxygen