Corrosion of iron wires using tap water, de-ionised water, oxygen, oil, salt, etc. in petri dishes.

1. Y E A R 1 0 – C O M P O U N D S A N D R E A C T I O N S
CORROSION OF IRON
J. Banks

2. AIM & HYPOTHESIS
• To investigate which
chemicals affect the rate
of corrosion of iron.
• What do you expect will
happen?
• Which chemicals do
you think will have the
greatest/least affect on
the rate of iron rusting?

3. EQUIPMENT
• 20mL Tap water
• 20mL De-ionized water
• 5 x Iron wire strips (2cm
each)
• 1 x teaspoon Salt
• 5 x Petri dishes
• 10mL Oil
• 5 x Paper towel (4x4cm
each)
• Sand paper
• Marker pen
• Measuring cylinder

4. RISK ASSESSMENT
Risk Injury Prevention
Metal Wire has sharp ends
Rust/tetanus
Can you think of any others?

5. METHOD
1. Cut the iron wire into 5
x lengths of 2cm each.
2. Using the sandpaper,
scrape the surface of
each length of wire until
the surface is shiny.
3. Place a piece of 4x4cm
paper towel in each
petri dish and 1 x length
of iron wire in the
centre of each.
4. Label one of the petri
dishes ‘Air’.
5. Label the second ‘tap
water’ and, using the
measuring cylinder, fill the
petri dish with 10mL of tap
water.
6. Label the third ‘de-
ionized water + oil’ and ,
using the measuring
cylinder add 10mL of de-
ionized water and 10mL of
oil.

6. METHOD
7. Label the fourth
petri dish ‘tap water +
salt’. Mix 10mL of tap
water and salt and add the
solution to the petri dish.
8. Label the last petri
dish ‘de-ionized water’
and using the measuring
cylinder add 10mL of de-
ionized water to it.
9. Leave the petri
dishes to rest for 3 days
and observe the amount
of corrosion has occurred
in each petri dish.
10. Record your
observations in a table.

7. RESULTS
• Draw an appropriate table for your observations.

8. WORD EQUATION
• Metal + water + oxygen  Rust (Metal oxide)
• Metal + water + oxygen + salt  A lot of rust (Metal
oxide)

9. DISCUSSION
1. Was the experiment valid? What evidence do you
have for your answer?
2. Which chemicals caused iron to corrode? Which of
these caused more corrosion?
3. Were there any changes you could make to the
experiment to make it better for next time?
4. Were your results the same as the other groups in
your class? How does checking other results
improve the overall experiment?

10. CONCLUSION
• Which substances cause iron to rust?
• Does this support or reject your hypothesis?
• Was the aim answered?