Simple Science Experiment: Clean a Penny (2024)

FAQs

How to do the penny cleaning experiment? ›

Copper oxide dissolves in water, but it usually takes a long time. The combination of vinegar (a weak solution of acetic acid), and table salt (sodium chloride) helps to dissolve the copper oxide, and also forms the blue copper(II) ion, which is soluble in water. The penny becomes shiny again!

The salt and acetic acid in vinegar do the trick. Hot sauce, like Tabasco or taco sauce, also will remove the oxides off pennies. As in ketchup, salt and vinegar are both in hot sauce. co*ke and off-brand colas will quickly remove the tarnish.

The vinegar made its penny shiny. Pennies become dull over time as copper on the surface reacts with oxygen from the air. The two elements combine to form dark chemicals called copper oxides. The acetic acid in vinegar dissolves these chemicals and leaves the copper surface of the penny looking shiny.

Conclusion: We found that the vinegar did the best job of cleaning the coins. No-one predicted this. This is because the vinegar contains an acid which helps to dissolve the dirt. Cola also contains this acid, but not as much.

Pennies are made out of a metal called copper. The copper mixes with oxygen, the same gas that we breathe. This cause something called oxidation and makes the penny look dirty. Lemon juice has acid in it that removes the dirty color or oxidation and makes the penny nice and shiny again!

Vinegar and lemon juice both work really well for cleaning pennies. But, ketchup was the clear winners for our pennies, with soy sauce next, maybe with a little more time they would have gotten a little bit cleaner. This is a fun experiment to try with younger kids!

Has a cashier ever given you your change and you cringed at the grimy and oily feel of the coins? Hydrogen peroxide will fix that. Hydrogen peroxide will dissolve the years of dirt on the coins and sterilize them.

The vinegar and salt mixture dissolves the outer layer of dirt. Flip the pennies over and wait another 30 seconds. Then remove them, rinse them with water, and dry. Now you have two clean, shiny pennies!

Ketchup contains vinegar, a weak acid, which breaks down the copper oxide on the surface of the penny. The salt in the ketchup goes on to add dissolved chloride ions to the mix. These ions bond with the copper, forming copper chloride. The copper chloride helps the vinegar further break down the copper oxide.

What is the science experiment with pennies? ›

When you place the pennies in the salt and vinegar solution, the acetic acid from the vinegar dissolves the copper oxide, leaving behind shiny clean pennies. After the 5 minutes required for 'Shiny Clean Pennies', take half of the pennies out of the liquid and place them on a paper towel to dry.

Hypothesis. I believe that the vinegar and salt will clean the pennies better compared to the other solutions because vinegar mixed with salt creates an acid that can clean what is called copper oxide which in other words is the rust on the penny.

The attraction of water molecules to other substances, like soil or glass, is called adhesion. As drops of water are added onto a penny, the adhesive force between the water and the penny keeps the water from falling off.

For a more hands-on approach to coin cleaning, try this method: Add a small amount of water to a tablespoon of baking soda to form a paste. Apply the paste to each coin using an old toothbrush and scrub gently. Rinse the coins to reveal the now-shiny surfaces.

STEP4 - Pop your coins into your glass of co*ke. STEP5 - Sit back and wait but you should be able to see a difference in the colour of your coins within about an hour.

When copper oxidizes, it turns a blue-green color, forming a compound called malachite. In Bowl 2, the vinegar and salt create a chemical reaction. This reaction dissolves the copper oxide (the dirty looking spots) and some of the copper on the outside of the penny. The result is a shiny looking penny!