Refining copper using electrolysis

Refining copper using electrolysis

ZIMSEC O Level Combined Science Notes: Experiment: Purification of copper using electrolysis

Aim: To investigate the process of refining copper using electrolysis

Materials: two strips of copper, sandpaper, copper sulphate solution, 12 volt dc supply/battery, beaker, ammeter/bulb


  1. Clean two strips of copper using sandpaper
  2. Place them in a solution of copper sulphate in a beaker
  3. Set up the circuit as shown in the diagram above
  4. Connect the electrodes to a battery
  5. Allow the current to flow for five minutes
  6. Carefully remove the electrodes from the solution and examine them

Observations and results

Electrolysis of copper. Image credit

Electrolysis of copper. Image credit

  • The cathode/negative electrode becomes thicker as copper is deposited onto it
  • The positive/anode electrode becomes thinner copper dissolves from it
  • The colour of the copper sulphate solution remains the same
  • as the copper taken from the copper sulphate solution at the negative electrode
  • is replaced by copper dissolving into the solution at the positive side
  • Any impurities in the copper at the positive side are left behind and fall into the solution


  • Copper can be purified using electrolytic purification

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