Electrolysis in aqueous Solutions

• in aqueous Solutions, there will be hydrogen ions (H+) and hydroxide ions (OH- ) from the water
• • At the cathode if H+ ions and metal ions are present Hydrogen gas will be produced if the metal is more reactive than hydrogen
  • If the metal is less reactive than hydrogen, a solid layer of pure metal is produced instead
• • At the anode, if OH- and halide ions are present, molecules of the halide (Chlorine, bromine or iodine) will be formed
  • If no halides are present, Oxygen will be formed
• Half equations:

  • show the reactions at the electrodes
  • Number of electrons needs to be the same

  e.g

  Negative electrode: 2H+ + 2e- = H2

  positive electrode: 2Cl- = Cl2- + 2e-