Electrolysis C2

Electrolysis C2

1. General

   • electrolysis: splitting up with electricty
   • liquid
     • to conduct electricity
     • electrolyte

2. Cathode

   • negative
   • gives out electrons
     • reduction reaction
       • gain of electrons
     • +ve ions attracted here

3. Anode

   • takes in electrons
   • positive
   • oxidation
     • loss of electrons

4. Sodium Chloride

   • dissolved in water
   • hydrogen, chlorine, sodium hydroxide
   • Hydrogen gains an electron at the cathode
   • Chlorine is produced at the anode
     • Chloride is an anion
   • sodium remains in solution
     • more reactive than hydrogen
       • Cation (ion)
     • NaOH left

5. Lead Bromide

   • Lead at cathode
   • Bromine at anode
   • Molten

6. Extracting Aluminium

   • from Bauxite ore
   • has a high melting point (2000C)
     • very expensive
     • so is dissolved in Cryolite
       • brings temp. down to 900C
         • easier and cheaper
   • Carbon electrodes
     • conduct electricity
     • Aluminium at cathode
     • Oxygen at anode
       • reacts with Carbon anode
         • Carbon Dioxide
           • replace anodes