RP3 - Electrolysis

• What is the aim of the electrolysis experiment?

  Investigate aqueous solutions with inert electrodes
• What equipment is needed for the electrolysis experiment?

  • 0.5 M copper(II) chloride solution
  • 0.5 M sodium chloride solution
  • Petri dish lid with bored holes
  • Two carbon rod electrodes with support bungs
  • Two crocodile/4mm plug leads
  • Low voltage power supply
  • Blue litmus paper
  • Forceps
• Why should the electrodes not touch during the experiment?

  To prevent short-circuiting and ensure proper electrolysis
• What should be done after adding copper chloride solution to the beaker?

  Add the lid and insert electrodes
• What voltage should the power supply be set to during the experiment?

  4V
• What is the purpose of holding litmus paper near the positive electrode?

  To observe any color change indicating reaction
• What should be observed at the negative electrode after turning off the power supply?

  Record observations at the electrodes
• What are the steps for repeating the experiment with sodium chloride?

  1. Add 50cm​3​ of sodium chloride solution to a beaker.
  2. Add the lid and insert electrodes.
  3. Attach crocodile leads to the electrodes.
  4. Set power supply to 4V and switch on.
  5. Hold litmus paper near the positive electrode.
  6. Turn off power supply and observe negative electrode for effervescence.
  7. Record observations at the electrodes.
• What safety precautions must be taken during the experiment?

  Wear safety goggles and ensure ventilation
• Why is it important to ventilate the room during the experiment?

  To avoid toxic chlorine gas accumulation
• What type of gas is produced that requires ventilation?

  Chlorine gas
• What observations should be recorded during the electrolysis of copper(II) chloride and sodium chloride?

  • Color change of litmus paper
  • Presence of gas bubbles at electrodes
  • Any other visible changes at electrodes