Simple Voltaic Cell

Explain the production of electricity in the simple voltaic cell.

  1. Magnesium is more electropositive than copper.  Magnesium is the negative terminal.
  2. Each magnesium atom donates two electrons to form a magnesium ion.  Mg --> Mg2+ + 2e-
  3. The flow of electrons from the magnesium ribbon to the copper through the external circuit results in the production of electricity.
  4. The hydrogen ions from the electrolyte(sodium chloride solution) are discharged at the copper plate by accepting electrons to form hydrogen gas.  2H+  + 2e- --> H2
What is the observation at each of the terminal? 

Please respond by leaving your answer in the comment box.


  1. negative terminal - magnesium metal corrodes
    positive terminal -bubbles of colourless gas produced

  2. Alya, it's better to said magnesium strip becomes smaller/thinner than using "corrode"...Thanks for leaving your comments... Enjoy learning chemistry through chem2u..

  3. How about if we use potassium sulphate as electrolyte? Is there any changes?