Electrolysis

• What is electrolysis used for in this context?

  To separate the elements in insoluble ionic compounds
• What is an electrolyte?

  A liquid or solution that contains an ionic compound
• Why must the ions in the electrolyte be free to move?

  To allow the electrolysis process to occur
• What would you do if the ionic compound is insoluble like lead bromide?

  You would melt it to create a molten liquid
• What ions are present in molten lead bromide?

  Positive lead ions and negative bromide ions
• What are the electrodes made of?

  Solid conductors, generally made of metal or carbon
• What is the positive electrode called?

  Anode
• What is the negative electrode called?

  Cathode
• Why do we need a power supply in electrolysis?

  To drive the flow of electrons between the electrodes
• What does the term electrolysis literally mean?

  Splitting up with electricity
• What happens to the negative bromide ions during electrolysis?

  They are attracted to the positive anode and discharged
• What do bromide ions form when discharged at the anode?

  Bromine gas
• What happens to the positive lead ions during electrolysis?

  They are attracted to the negative cathode and discharged
• What is formed when lead ions are discharged at the cathode?

  Pure lead
• What is the process occurring at the anode with bromide ions?

  Oxidation to bromine, losing one electron each
• What is the process occurring at the cathode with lead ions?

  Reduction to pure lead by gaining two electrons
• How do electrons move during the electrolysis process?

  From the negative bromide ions to the positive lead ions