Electrolysis

• What is the main focus of the video lesson?

  Investigating electrolysis of aqueous solutions
• Why is it important to learn the details of the electrolysis experiment?

  It is a required practical for exams
• What are the two aqueous solutions used in the electrolysis experiment?

  • Copper(II) chloride
  • Sodium chloride
• What is the first step in the electrolysis of copper(II) chloride solution?

  Pour 50 cm³ of solution into a beaker
• What type of dish is placed over the beaker during the experiment?

  A plastic petri dish
• Why are carbon graphite rods used as electrodes?

  They are unreactive and inert
• What must not happen between the two electrodes during electrolysis?

  They must not touch each other
• What voltage is set on the power supply during the experiment?

  Four volts
• What happens at the cathode during the electrolysis of copper(II) chloride?

  Copper is discharged and coats the electrode
• What indicates that chlorine gas is produced at the anode?

  Bubbles of gas and a chlorine smell
• What happens to blue litmus paper when exposed to chlorine gas?

  It becomes bleached
• What are the products formed during the electrolysis of copper(II) chloride solution?

  • Copper is discharged at the cathode
  • Chlorine gas is discharged at the anode
• What is the first step in the electrolysis of sodium chloride solution?

  Pour 50 cm³ of sodium chloride solution
• What gas is produced at the anode during the electrolysis of sodium chloride?

  Chlorine gas
• How can you confirm that the gas produced at the cathode is hydrogen?

  By testing it with a lit splint
• What sound does hydrogen gas produce when ignited?

  A squeaky pop sound
• What are the key observations during the electrolysis of sodium chloride solution?

  • Bubbles of chlorine gas at the anode
  • Bubbles of hydrogen gas at the cathode