Can You Clean Pennies With Acids?
Dirty pennies in Vinegar+salt solution
Materials
4 old, dirty pennies
2 tablespoons white vinegar (Please use vinegar from “Let’s talk Chalk” experiment)
One plastic container w/lid
Materials from your house
1 teaspoon salt
Paper towels
How do I begin?
1. Add a teaspoon of salt in the plastic container. Now add 2 tablespoons of vinegar and stir well.
2. Now put 2 of the dirty pennies in the container.
3. Count to 15 slowly and take the pennies out.
4. Rinse the pennies in water. Check out that shine!
5. Get the remaining two dirty pennies and put them in the vinegar and salt solution.
6. Wait for another 15 seconds, but this time, do not rinse them off.
7. Place them on a paper towel to dry off. Now wait.
8. What happens?
What just happened?
Good ole' chemistry is at work here. Vinegar is acidic, as you well know by now. This acid in the vinegar reacts to the salt, which is a base. It removes the copper oxide which makes the pennies dull and dirty.
The pennies will turn greenish-blue in a little while as a chemical called malachite forms on your pennies, when you leave it out to air-dry. This is because the copper in the pennies reacts with the oxygen in the air, to form the greenish-blue malachite.
Exploring Further
1. Try it with other acids like lemon juice or orange juice. Which is more effective?
2. If you increase or decrease the salt, does it make a difference?
4 old, dirty pennies
2 tablespoons white vinegar (Please use vinegar from “Let’s talk Chalk” experiment)
One plastic container w/lid
Materials from your house
1 teaspoon salt
Paper towels
How do I begin?
1. Add a teaspoon of salt in the plastic container. Now add 2 tablespoons of vinegar and stir well.
2. Now put 2 of the dirty pennies in the container.
3. Count to 15 slowly and take the pennies out.
4. Rinse the pennies in water. Check out that shine!
5. Get the remaining two dirty pennies and put them in the vinegar and salt solution.
6. Wait for another 15 seconds, but this time, do not rinse them off.
7. Place them on a paper towel to dry off. Now wait.
8. What happens?
What just happened?
Good ole' chemistry is at work here. Vinegar is acidic, as you well know by now. This acid in the vinegar reacts to the salt, which is a base. It removes the copper oxide which makes the pennies dull and dirty.
The pennies will turn greenish-blue in a little while as a chemical called malachite forms on your pennies, when you leave it out to air-dry. This is because the copper in the pennies reacts with the oxygen in the air, to form the greenish-blue malachite.
Exploring Further
1. Try it with other acids like lemon juice or orange juice. Which is more effective?
2. If you increase or decrease the salt, does it make a difference?