Electrolysis

• Solid ionic compounds cannot conduct electricity. This is because the ions are in fixed positions and are not free to move and carry a charge
• In solid ionic compounds, the ions have a regular repeating arrangement called an ionic lattice. The ions are held together by strong electrostatic forces of attraction so the ions are not free to move. The lattice is formed because the ions attract eachother and form a regular pattern with oppositely charged ions next to eachother.
• When an ionic compound is molten or dissolved in water the forces of attraction are broken and the ions are free to move. These liquids and solutions( electrolytes) can now conduct electricity.
• In electrolysis there are two electrodes. These are made from conducting materials such as graphite or a metal.
• The negative electrode is called a cathode
• The positive electrodes called anode
• The cathode is attached to the negative terminal of a battery. The cathode is covered with electrons
• The anode is attached to the positive terminal of the battery. The anode has a lack of electrons
• Positively charged ions are attracted to the negative electrodes because opposite charges attract. The ions gain electrons from the cathode to form their atoms. This is a reduction reaction because ions are gaining electrons
• negative Ions are attracted to the positive electrode, anode. At the anode the ions lose electrons to form their atoms. This is a oxidation reactions because the ions are losing electrons
• Electrolytes 


  Ionic compounds that are molten or dissolved in water
• Electrolysis 


  The process of breaking down electrolytes using electricity
• During electrolysis an electric current is passed through an electrolyte
• The metal element is produced at the cathode when a molten ionic compound undergoes electrolysis
• The non metal element is produced at the anode when a molten ionic compound undergoes electrolysis
• Test for chlorine gas

  Insert Damp blue litmus paper into the test tube where the unknown gas is. If the litmus paper turns white chlorine is present