Oxidation and Rust: How Is Rust Produced?
One of the most common oxidation reactions is the production of rust, otherwise known as corrosion. Iron readily combines with water and oxygen to form rust.
In this experiment, you will explore the process of iron oxidation, which produces rust. You will see the result of the depletion of oxygen as this element is removed from the air to combine with iron.
Level of Difficulty
Easy/moderate; a lighted candle is involved, so adult supervision is required.
Materials Needed
- 2 equal-sized pieces of steel wool (Do not use scouring pads that contain soap.)
- 2 identical glass jars with metal lids
- water
- 2 small birthday candles
- matches
- a small amount of modeling clay
- stopwatch
Approximate Budget
- $5 to $7 if you need to purchase steel wool, modeling clay and/or candles.
Timetable
3 days.
Step-by-Step Instructions
- Wet one piece of steel wool and place it in one of the jars. In the other jar, place a dry piece of steel wool. Label each jar carefully.
- Close both lids tightly and place the jars in a cool, dark place for three days.
- Have an adult light one of the candles.
- Open the experimental jar and have the adult drop in the candle. Quickly close the jar again.
- Use the stopwatch to time how long the candle burns. Record the time on a chart like the one illustrated.
- Repeat Steps 3 to 5, having your adult helper drop the other lighted candle in the control jar.
- After both candles have burned, remove the steel wool from both jars and record what you find.
Summary of Results
Study your results, comparing the amounts of rust on each piece of steel wool and the times the two candles burned. The more rust you observe, the more oxidation occurred. The shorter time the candles burned, the less oxygen was present in the jars, showing that more oxidation occurred. What did you discover? Was your hypothesis supported? Write a paragraph summarizing and explaining your results.
Troubleshooter's Guide
Problem: No rust showed on the either piece of steel wool.
Possible causes: You did not put enough water on the experimental steel wool. Try wetting it more, or putting a small amount of water in the base of the jar before leaving it.
You did not leave the jars long enough. Try leaving both jars for several more days.
Problem: The candles burned the same length of time.
Possible causes: You let in too much outside air when you opened the jars. Open and close the jars as quickly as possible so little outside air will have an opportunity to mix.