How fast can you rust?
Activity Instructions
1. Gather materials:
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Plastic cup
Plastic bowl
Scissors
Ruler
Water resistant Marker
2. Cut out a 2 cm tall piece into the top of the plastic cup.
3. Mark 4 cm from the top of the cup with a water resistant marker.
4. Fill up the bowl with water, 4 cm high. Try to be precise here.
5. Calculate the volume that makes up the lower 8 cm of the cup.
6. Get the steel wool:
IMPORTANT: While working with steel wool safety glasses must be worn. Do
not rub your eyes or touch your face while handling steel wool. Wash your
hands after you're done.
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Get a piece of steel wool. Keep steel wool OVER the cover while working with it.
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Dip wool into the acetic acid briefly and let drain over the acid bath.
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Put wool into plastic cup.
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Tape the wool to the bottom so it doesn't fall out when you flip the cup on it's
head.
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Wash hands if you touched the steel wool.
7. Gently flip the cup and lower it into the bowl with the water. Tilt it to let air escape.
8. Make sure that the water level in the cup and the bowl are even
Discuss in your group: What will happen to the iron in the steel wool when it starts rusting?
Use your knowledge of chemistry to predict the chemical reaction.
Observe: Record what is happening in your science notebook. Measure how much the
water rose up, and calculate the new volume. What percentage of air is oxygen?
Discuss in your group: Why do you think the water level rose in the cup? Where did the
oxygen go? What happened to the iron? Write down your conclusions in your science book.