RP03 - Electrolysis

• What is the first step of the electrolysis practical?

  Set up a beaker and pour in the electrolyte solution (e.g. sodium chloride solution).
• What is the second step of the electrolysis practical?

  Insert two inert electrodes (e.g. carbon or graphite) into the solution.
• What is the third step of the electrolysis practical?

  Connect the electrodes to a power supply using wires and crocodile clips.
• What is the fourth step of the electrolysis practical?

  Turn on the power supply to begin electrolysis.
• What is the fifth step of the electrolysis practical?

  Observe and record the products formed at each electrode.
• What is the sixth step of the electrolysis practical?

  Test any gases produced:

  Hydrogen → squeaky pop test

  Chlorine → damp blue litmus paper bleaches
• What is the seventh step of the electrolysis practical?

  Turn off the power supply and clean the equipment safely.
• What forms at the cathode during electrolysis of sodium chloride solution?

  Hydrogen gas
• If the metal is more reactive than hydrogen, what is produced?

  hydrogen gas
• If the metal is less reactive than hydrogen, what happens?

  The metal is deposited
• What are the only three metals that are deposited?

  Copper, silver and gold
• How should you remember the three metals that are deposited?

  Cops (Copper)

  Royalty (Silver and gold)
• Why is hydrogen produced instead of sodium?

  Because hydrogen is less reactive than sodium.
• Why is chlorine produced at the anode?

  Because chloride ions (Cl⁻) are halide ions and are discharged instead of oxygen.
• What happens if the solution contains a halide ion (i.e., Cl⁻, Br⁻, I⁻)

  The halogen gas is produced
• What happens if there is no halide ion present?

  Oxygen gas is produced
• What is oxygen gas produced from

  The hydroxide ions (OH-) in the water