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Questions 5.5

  1. Are the metals used to electroplate other items reactive or unreactive? Explain your answer.
  2. Should the item to be electroplated be made the anode or cathode? Explain your answer.
  3. From your knowledge of electrolysis, must electroplated item be a conductor of electricity? Explain.
  4. Draw a fully labelled circuit diagram to show how you would electroplate graphite rod using a battery of two electric cells, aqueous copper (II) sulphate solution as electrolyte and copper metal as anode. Represent an electric cell with the conventional symbol.



Answers to Questions 5.5

  1. They are generally unreactive (or less reactive). Being able to retain their attractive appearance implies that they do not tarnish; that is they do not react with air, water and other reactive substances around them.
  2. The item to be electroplated is made the cathode. This makes the item negative so that the positive metallic ions in the electrolyte can be attracted to it, be discharged and deposit on it as a coating.
  3. The item must be an electrical conductor. Otherwise the circuit will be incomplete, and electrons and ions will not move.