Clean Your Pennies...

This activity is a safe way to use an acid to clean pennies.

Ages: This is for Big Kid Scientists only

Materials:  dull pennies, 1/4 c white vinegar, 1 tsp salt, glass or plastic bowl, water, paper towels

Procedure:

• Pour the salt and the vinegar into the bowl.  Vinegar is actually a weak acid - acetic acid.
• Stir until the salt is dissolved into the vinegar.
• Place the pennies into the solution.  What do you notice?
• Leave the pennies in the solution for 5 minutes.  What do you notice when you remove the pennies?
• Leave half the pennies on a paper towel and rinse the other half off in cool water.  
• Leave both sets of pennies for about an hour.  What do you notice about the two sets?