electrolysis

• What is electrolysis used for?

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

  A liquid containing an ionic compound
• Why must ions in an electrolyte be free to move?

  To conduct electricity during electrolysis
• How would you prepare an electrolyte from copper sulfate?

  Dissolve it in water
• What must be done to lead bromide to use it in electrolysis?

  It must be melted
• What ions are present in molten lead bromide?

  Lead ions and bromide ions
• What are the electrodes 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
• What does the term electrolysis literally mean?

  Splitting up with electricity
• What happens to bromide ions at the anode?

  They are oxidized to bromine gas
• What occurs when lead ions reach the cathode?

  They are reduced to form pure lead
• What are the steps involved in the electrolysis of molten lead bromide?

  1. Melt lead bromide to create a molten electrolyte.
  2. Connect electrodes to a power supply.
  3. Pass electric current through the electrolyte.
  4. Bromide ions are oxidized at the anode to form bromine gas.
  5. Lead ions are reduced at the cathode to form pure lead.
• What will happen to the bromine gas produced during electrolysis?

  It will float off
• What is produced at the cathode during electrolysis of lead bromide?

  Pure lead
• What is the significance of oxidation and reduction in electrolysis?

  • Oxidation: Loss of electrons (bromide to bromine)
  • Reduction: Gain of electrons (lead ions to lead)
  • Essential for separating elements in compounds