Chemistry for Kids: Penny Change Experiment

This two-part chemistry experiment uses a household acid, vinegar, to clean copper pennies. Kids can observe the oxidation process as the copper in the pennies reacts with oxygen in the air to first form copper oxide and then malachite. Get your kids interested in STEM → science, technology, engineering, and math with this easy chemistry project!

Science Lab Supplies

• Free printable lab notebook with full instructions (download in the free printable library)

The lab book contains three easy science experiments for kids and contains areas to record your notes and observations. You can print it on card stock or plain paper and assemble it with ring clips or staples. It would be perfect for a science party.

Penny Change Experiment Supplies

• 3 dull or dirty looking pennies
• 1/4 cup white vinegar
• 1 teaspoon table salt
• paper towel or cotton pad
• small non-metal bowl
• Small non-metal container with lid

Penny Change Experiment Instructions

Part 1 – Dull to Shiny

• Pour the vinegar and salt into the small non-metal bowl and stir to dissolve.

• Put 3 pennies into the bowl for about 30 seconds.

• The pennies are now shiny and look new!  Take out the pennies and rinse them with fresh water. Place them on a paper towel to dry off.

Penny Change Experiment Instructions

Part 2 – Shiny to Green

• Fold a paper towel or cotton pad to fit the bottom of your container with a lid.
• Wet the paper towel or cotton pad with a few drops of vinegar.
• Put one penny on the wet pad and cover with the lid. (The lid keeps the vinegar from drying out.)

• Put one penny on a dry pad or paper towel.
• Dip one penny in your salt/vinegar mixture and place it on a dry pad or paper towel.
• Observe your pennies at 1, 2, 3 and 8 hours.

Experiment Tip

Pennies made in 1982 or earlier are made of solid copper, use them in this reaction to make it work even better! Pennies made after 1982 are made from copper and zinc, they react a little less.

Experiment Follow-Up

Complete the lab notes section of the free printable lab notebook  (available in the free printable library) with your kids. Have them record their predictions and observations. Which pennies oxidized the most quickly? Why do you think this happened? Look at the back of the penny on the vinegar pad. What does it look like? Why?

More Cool Science Experiments for Kids

Make sure to check out my post about Cool Science Experiments for Kids, download the free lab notebook (available in the free printable library), and check out my Glitter Tornado &  Fishing for Ice projects.

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