(i) Electrolysis

• Describe how to set up electrolysis for aqueous solutions

  1. Get two inert electrodes and clean their surfaces with sandpaper to ensure that the metals won’t react with oxygen
  2. Place both electrodes into a beaker containing electrolytes dissolved in water
  3. Connect the electrodes to a power supply using crocodile clips and wires. When switched on, a current will flow and electrolysis will start
• Solid ionic compounds do not conduct electricity because they do not have freely moving ions that can carry a charge
• Molten or aqueous ionic compounds can conduct electricity because they have freely moving ions that can carry an electric charge
• The cathode is where the cations will dissociate; the anode is where the anions will dissociate
• In aqueous solutions at the cathode, if the ion is more reactive than hydrogen then hydrogen gas dissociates at the cathode (because hydrogen is more electronegative than those metals)
• In aqueous solutions at the cathode, is the ion is less reactive than hydrogen then a metal is formed at the cathode
• In aqueous solutions at the anode, is halide ions are present then the halide ions will dissociate to form a halogen. If halide ions are absent, then the hydroxide ions dissociate to form oxygen