Rusting iron nails. Image credit

Rusting iron nails. Image credit

ZIMSEC O Level Combined Science Notes: Experiment: Investigating the corrosion of plated of plated iron

Aim: To investigate the corrosion of  iron

Materials: ferroxyl indicator (turns blue when iron rusts), iron nails, sand paper, magnesium ribbon, zinc, copper, five test tubes, paint


  1. Place ferroxyl indicator to a depth of about 5cm in five test tubes
  2. Clean the nails with sand paper
  3. Place an iron nail in one of the test tubes
  4. Wrap a small piece of magnesium closely around the top of a clean nail and place it in another test tube
  5. Repeat with two more nails wrapping them with zinc and copper instead
  6. Paint one nail with nail vanish or paint before dipping them into the solution
  7. Observe the results

Observation and results

  • The nail in step 3 and the one wrapped in copper rusts  and the ferroxyl indicator turns blue to indicate rusting
  • Zinc and Magnesium protect the iron nail from rusting via sacrificial corrosion even when only part of the nail is wrapped
  • The unwrapped nail and the one wrapped in copper are corroded

To access more topics go to the Combined Science Notes page.