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How do Acids Clean Pennies?

I'm a sixth grader, and I'm doing a lab about cleaning pennies right now. I used stuff like vinegar ⇦in bulk on eBay or Amazon [affil links] , lemon juice, and lime soda because I heard that acids clean pennies better. How do the acids clean the pennies?

Stephi
- Palo Alto, California, USA
2001

Yes my 4th grader has a project on solutions that cleans pennies - I need to know what type of solutions does this - and any idea on how we can present this project.

Bobbie Hereford
- Atlanta, Georgia
2003

A lemon with some salt will clean a penny.

Vexx E.
- New York City, New York, America
2003

A lemon will work but personally vinegar works better cause I am doing a penny experiment in the 8th grade and that is what we used we soaked pennies in vinegar for about 5 minutes we took the pennies out and they were clean. You know what? Ketchup works also.

Kaoru-Dono
- Cold Spring, Kentucky, USA
2003

I am also doing a science fair project about which liquids clean pennies the best. I tried to clean pennies with vinegar and it worked pretty well. I tried to clean a dollar coin and some silver coins with vinegar and it made a darkish brown stain. I guess vinegar is too strong of an acid to clean other coins with.

Minh P.
- Savannah, GA, USA
2003

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