Investigating the rusting or iron

Investigating the rusting of iron

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

Aim: Investigating the rusting (oxidation) of iron

Materials: 4 iron nails, 1 steel nail, a piece of copper/brass, 5 test tubes, cotton wool, solid calcium chloride, magnesium ribbon

Method

  1. Half fill two test tubes with water
  2. Put an iron nail in one test tube and label it A and a steel nail in another tube label it B
  3. Put an iron nail in a dry test tube and label it C and plug with a small piece of cotton wool on which a few pieces of calcium chloride are placed.
  4. Calcium chloride is a drying agent
  5. Wrap a piece of magnesium ribbon around and an iron nail and put it into the fourth test tube and label it D fill it with water
  6. Half fill the remaining test tube with boiled water. Put an iron nail with a layer of oil to exclude air and label the tube E
  7. Leave the test tubes for a few days and observe the results

Results and Observations

  • The iron nail in test tube A will be covered with a layer of rust after a few days
  • There is very little if any rust on the steel nail in test tube B
  • There is no rust observed on the iron nail in test tube C
  • There is no rust/little rust on the iron nail in test tube D
  • There is no rusting on the iron nail in test tube E

Conclusion

  • Iron is susceptible to rusting
  • Rusting can only occur in the presence of moisture (water) and air
  • Controlling humidity ( test tube C) prevents rusting
  • Galvanising using a more reactive metal such as zinc prevents the rusting of iron
  • Oiling reduces/prevents rusting

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