Experiment 5

Copper Plating

 

In this experiment you will discover if the nail used by the thief came from the Vinegar River flood by determining if nails soaked in a solution of vinegar, salt and dissolved copper will become copper plated.

I. Hypothesis
Tiny amounts of copper oxide and copper will dissolve from the surface of dull, dirty pennies (or any other copper or copper-plated coin) when placed in a vinegar salt solution. Afterwards, nails soaking in the same solution that was used to soak the pennies will cause a thin film of copper to adhere to the surface of the nails.

II. Materials needed

• 6 copper coated or copper alloy coins. (American Pennies, British Two Pence, and Five Cent Euros all work well.)
• 1/4 cup (60 milliliters) white vinegar
• 1 teaspoon (5 milliliters) salt
• A clear, shallow bowl (not metal)
• 3 clean steel or iron nails (not galvanized or coated)
• Paper towels

III. Procedure

1. Put the salt and vinegar in the bowl. Stir until the salt dissolves.
2. Dump all the coins into the liquid. After 20 minutes, take the coins out of the liquid. Put them on a paper towel to dry. Do the coins look any different than when you first put them into the solution?
3. Lean the nails against the side of the bowl so that only part of each one is in the liquid.
4. After an hour, take a look at the nails. Are the leaning nails two different colors? Leave the nails in the bowl overnight and check on them again in the morning. Do the nails in your bowl look like the nail that was used to post the note to the oorgave cactus?

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