Why Do Pennies Turn Green In Vinegar?

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  • 20 boring, filthy cents
  • One-fourth cup white vinegar
  • 1 salt shakerful
  • a transparent, little bowl (not metal)
  • two tidy steel nails
  • a neat steel bolt or screw
  • Printed towels

How long does a penny need to soak in vinegar before it turns green?

When exposed to oxygen and an acid, pennies in the “wild,” so to speak, turn green (which can be from fingers, food, the weather, and a bunch of other stuff).

But in this controlled setting, you can hasten the procedure by adding some air, vinegar, and salt.

However, initially, we had the pennies soaking in a substantial solution. The next day, when we replaced it with a paper towel dipped in vinegar, the pennies had gone green.

Our first setup, which is necessary for turning a penny green, may not have received enough oxygen, in my opinion.

What occurs when a penny is placed in vinegar?

Its penny was rendered bright by the vinegar. As copper on the surface reacts with oxygen from the air, pennies gradually lose their luster. Copper oxides are noxious compounds that are created when the two elements mix. These compounds are broken down by vinegar’s acetic acid, which also makes the copper surface of the penny appear bright. While soap can clean a variety of surfaces, it cannot dissolve copper oxides.

Younger children: Repeat the experiment using more pennies. Gather 10 pennies and count them one at a time with your youngster. Discuss the appearance of the pennies before putting them in the vinegar. Consider size, shape, and color. Repeat the experiment, rinse the pennies, and then resume your conversation. What makes the pennies unique? What is similar? Recount the pennies one last time before depositing them in your child’s piggy bank.

teen children: You immersed the penny in the vinegar for ten minutes in this experiment. What would happen if you left it on for 30 seconds, in your opinion? How long would you leave it on for? What would happen if you dipped the penny only partially into the vinegar? Try these theories with different pennies and make an educated guess. You can use other acidic liquids, such as lemon juice or pickle juice, if you run out of vinegar. Look how how they contrast!

What does a green penny represent?

Your green pennies have a patina, which is a term. Your copper penny’s surface has developed a thin layer called a patina as a result of “weathering and oxidization from the chemical procedure we just put the penny through.”

A thin covering of copper covers the Statue of Liberty. She has a patina like our green pennies since she is exposed to the weather and is surrounded by ocean. To polish her would take a lot of work!

Why do pennies in vinegar become blue?

Today, the Statue of Liberty is recognized for its enduring blue-green hue. It wasn’t always this identifiable color, though. The monument was a brilliant copper color, precisely like a penny, when it was initially exhibited to the American public in 1886. This is so that the Statue of Liberty’s surface, which is made of the same metal that is used to make pennies, can be seen. The Statue of Liberty changed from its glossy new penny color to its current green tint over the course of nearly twenty years of exposure to the elements. You guessed it, science can explain this change in color! The Statue of Liberty’s demise can be explained by a chemical process. A green oxcide is created when the thin copper sheets on the statue’s exterior react with the oxygen in the surrounding atmosphere. This copper oxcide, in the case of the Statue of Liberty, keeps reacting to produce copper carbonates, copper sulfide, and copper sulfate. The blue-green hue is created by these three major substances. The chemical reaction that gives the metal this color is simply a patina that develops over the metal to protect it from corrosion and deterioration.

Watch Oxidation Happen At-Home

I’ve been looking for easy scientific projects that can be completed at home and for which almost any household already has the necessary materials. The ideal low-maintenance exercise, this chemical reaction with pennies experiment teaches youngsters crucial chemical reaction principles and explains why the Statue of Liberty is the color it is today.

In this chemistry experiment, copper pennies are cleaned in one bowl using vinegar and salt, then turned green in another bowl using only vinegar. The copper oxide and some of the copper on filthy pennies dissolve in the water and are washed off the surface of the coin when it is immersed in vinegar and salt. The penny appears fresh new after being cleaned and rinsed. A penny will turn greener over a few hours if it is steeped in only vinegar, which speeds up the oxidation process.


Be aware that pennies minted in 1982 or earlier are solid copper coins; use these in this reaction to improve results. The reaction is weaker in pennies produced after 1982 since they are comprised of copper and zinc.

1.Line the bottoms of your tiny containers with paper towels that have been ripped to fit. Put one penny in each tiny basin.

2. Combine the salt and vinegar in a small non-metallic bowl and mix to combine. Only vinegar should be placed in the other tiny basin.

3. You should observe that the pennies in the bowl of vinegar and salt start to lose their outer, grimy covering after only 30 seconds. After turning the coins over, give them another 30 seconds to soak. After that, clean the pennies by wiping them in water. Ta-da! fresh, shiny pennies.

4. After approximately an hour, check on the pennies you placed in the vinegar and salt. A green covering should be forming on them. Check your pennies frequently to observe the changes—every 2 hours, 3 hours, 1 day, etc.

5. I was able to locate one cent from 1944 and one that was produced after 1982. To see if the vinegar and salt mixture may make them more shinier, I placed both back in. The 1944 penny was substantially cleaner than the 1982 coin, which is a combination of copper and zinc instead of the 1944 penny’s pure copper.

What is Going On?

A chemical process has taken place! When two reactants combine to create a completely new substance, this is referred to as a chemical reaction. Copper is used to make pennies. A blue-green substance called malachite is formed when the copper in the penny easily reacts with the oxygen in the air thanks to the vinegar on the paper towel.

Do green pennies have any value?

Most of us keep piles of pennies around the house and in the ashtrays of our cars. And a few of those antique pennies can be both extremely uncommon and extremely expensive.

The 1944 Steel Wheat Penny without a mintmark is one of the pennies with the highest value. One in pristine condition can sell for upwards of $110,000, and they are now valued at more than $77,000.

A 1943 Copper Wheat Penny is worth about $60,000, while a pristine one is worth close to $86,000. The value of a 1909-S V.D.B. is $2,250. The value of a 1923 Wheat Penny is $700. $450 can be paid for a 1909-S. Both the 1916 S Wheat Penny and the 1913 D Wheat Penny are worth $225. Do you need to clean your old coins? You may make a lot of money if you have the correct pennies. Spend some time looking at those pennies before you turn them in for cash since they might be worth. If you want to expand your collection of U.S. coins, feel free to look at some of our U.S. Mint coins for sale.