Electrolysis P2

• What process is used to extract reactive metals from their oxides?

  Electrolysis
• Why do metals often exist as oxides?

  They react with oxygen in the environment
• What is the first step to isolate pure metal from its oxide?

  Reduce the metal in the oxide
• How does carbon reduce metal oxides?

  Carbon displaces the metal to form pure metal
• Which metals can be reduced with carbon?

  Zinc, iron, and copper
• Why is electrolysis more expensive than reduction with carbon?

  It requires a lot of energy
• What is the role of an electrolyte in electrolysis?

  It allows ions to move freely
• Why can't solid aluminium oxide be used in electrolysis?

  Its ions are fixed in place
• What must be done to aluminium oxide before electrolysis?

  It must be melted into a molten state
• What mineral is mixed with aluminium oxide to lower its melting point?

  Cryolite
• What is the melting point of aluminium oxide?

  Over 2000 degrees Celsius
• What equipment is needed for electrolysis of molten aluminium oxide?

  A beaker, electrodes, and a power source
• What are the two types of electrodes used in electrolysis?

  Anode and cathode
• What happens to oxygen ions at the anode during electrolysis?

  They lose electrons and form oxygen atoms
• What is produced at the cathode during electrolysis of aluminium oxide?

  Molten aluminium metal
• What is the half equation for the reaction at the anode?

  Oxygen ions form oxygen atoms plus electrons
• What mnemonic helps remember oxidation and reduction?

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

  Aluminium oxide forms aluminium and oxygen
• What are the steps to extract aluminium from bauxite using electrolysis?

  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
  5. Pass electric current to separate aluminium and oxygen
• What occurs at each electrode during the electrolysis of aluminium oxide?

  • Anode: Oxygen ions lose electrons, forming oxygen gas
  • Cathode: Aluminium ions gain electrons, forming molten aluminium
• What are the characteristics of the electrolysis process?

  • Requires an electrolyte
  • Involves movement of ions
  • Produces pure elements from ionic compounds
  • Involves oxidation and reduction reactions