electrolysis

• describe electrolysis

  decomposing ionic compounds by passing electric charge between electrodes through an electrolyte
• describe electrolyte

  melted or dissolved ionic compound with ions free to move through the structure to conduct electricity
• describe positive electrode

  anode where oxidation occurs due to loss of electrons
• describe negative electrode

  cathode where reduction occurs due to gain of electrons
• describe process of electrolysis at anode

  1. negative ions attracted to anode
  2. discharge and oxidised at anode
  3. form element
• describe process of electrolysis at cathode

  1. positive ions attracted to cathode
  2. discharged and reduced at cathode
  3. form element
• describe electrolysis of ionic compounds

  metal - produced at cathode

  non metal - produced at anode
• describe electrolysis of aluminium oxide

  electrolyte - aluminium oxide and cryolite (lower melting point)

  carbon anode - constantly replaced (react with oxygen to form carbon dioxide)
• describe electrolysis of aqueous solution at anode

  1. negative ions - non metal and hydroxide - attracted
  2. hydroxide or halide ion discharged and oxidised
  3. oxygen or halogen produced
• describe electrolysis of aqueous solution at cathode

  1. positive ions - metal and hydrogen - attracted
  2. least reactive ion discharged and reduced
  3. least reactive element formed