Electrolysis

• What should you be able to describe by the end of the video on electrolysis?

  How to investigate what happens when aqueous solutions undergo electrolysis
• What are the two aqueous solutions used in the electrolysis experiment?

  • Copper(II) chloride
  • Sodium chloride
• How much copper(II) chloride solution is poured into the beaker?

  Approximately 50 centimeters cubed
• What is the purpose of the plastic petri dish in the electrolysis setup?

  To cover the beaker and hold the electrodes in place
• What material are the electrodes made of in this experiment?

  Carbon graphite
• Why are the carbon graphite electrodes considered inert?

  Because they do not react during the electrolysis process
• What must not happen between the two electrodes during electrolysis?

  They must not touch each other
• What happens when the electrodes are connected to the low-voltage power supply?

  The electrolysis process begins
• What is observed at the cathode during the electrolysis of copper(II) chloride solution?

  The cathode is coated with copper
• Why is copper discharged at the cathode during electrolysis of copper(II) chloride?

  Because copper is less reactive than hydrogen
• What gas is produced at the anode during the electrolysis of copper(II) chloride?

  Chlorine gas
• How can you confirm that chlorine gas is produced at the anode?

  By holding damp blue litmus paper near the anode, which becomes bleached
• What are the results of electrolyzing copper(II) chloride solution?

  • Copper is discharged at the cathode
  • Chlorine gas is discharged at the anode
• What is the procedure for electrolyzing sodium chloride solution?

  Pour approximately 50 centimeters cubed of sodium chloride solution into a beaker and turn on the power supply
• What is observed at the anode during the electrolysis of sodium chloride solution?

  Bubbles of gas are produced that bleach damp blue litmus paper
• What gas is produced at the cathode during the electrolysis of sodium chloride solution?

  Hydrogen gas
• Why is hydrogen gas discharged at the cathode during the electrolysis of sodium chloride?

  Because sodium is more reactive than hydrogen
• How can you test for hydrogen gas produced at the cathode?

  By collecting it and testing with a lit splint, which produces a squeaky pop
• What are the key observations during the electrolysis of sodium chloride solution?

  • Chlorine gas is produced at the anode (bleaches litmus paper)
  • Hydrogen gas is produced at the cathode (squeaky pop test)
• Where can students find questions related to the required practical on electrolysis?

  In the revision workbook linked in the video