Electrolysis

Cards (9)

  • Investigating what happens when aqueous solutions undergo electrolysis
    1. Pour approximately 50 cm^3 of copper(II) chloride solution into a beaker
    2. Place a plastic petri dish with two holes over the beaker
    3. Insert a carbon graphite rod into each hole (electrodes)
    4. Attach crocodile leads to the rods and connect to a low-voltage power supply
    5. Select 4 volts on the power supply and switch it on
  • Electrodes
    • Carbon graphite rods are unreactive (inert)
    • The two electrodes must not touch each other to avoid a short-circuit
  • Copper is less reactive than hydrogen

    Copper is discharged at the cathode
  • Electrolyzing a solution containing a halide ion

    The halogen is discharged at the anode
  • Chlorine gas is produced at the anode during electrolysis of copper(II) chloride solution
  • Holding damp blue litmus paper near the anode shows the gas is chlorine (it becomes bleached)
  • Electrolyzing sodium chloride solution
    1. Pour approximately 50 cm^3 of sodium chloride solution into a beaker
    2. Turn on the low-voltage power supply
  • Electrolyzing sodium chloride solution
    Chlorine gas is produced at the anode, hydrogen gas is produced at the cathode
  • Hydrogen gas can be tested by collecting it and testing with a lit splint (produces a squeaky pop)