Copper Plating Experiment

Yesterday in chemistry we copper plated an iron nail. If you look at the picture below, you can see that the nail has taken on a copper color.

Copper plate a nail experiment

Want to try it yourself? You’ll need:

  • The juice from 2 lemons or 1/2 cup of vinegar (We used lemon juice.)
  • Plastic cup or ceramic bowl (We used a disposable cup.)
  • 10 to 20 dull pennies (We used about 20.)
  • A pinch or couple shakes of salt
  • An iron nail (ungalvanized)
  1. Put the lemon juice into the cup.
  2. Place your pennies in the bottom of the cup, inside the juice.
  3. Add the salt.
  4. Place the nail inside the cup and leave it for at least 30 minutes. We left our nail in overnight. When you take it out it should be coated with enough copper for you to notice!

Why does it do that? The lemon juice dissolves the copper on the pennies and this produces copper ions. An ion is an atom that either has extra electrons or is missing some electrons.
The copper ions are attracted to the iron in the nail and build up, until there is a visible coat of copper on the nail.

Here’s a close-up of the nail, which is now, roughly, the color of a penny, when before it was almost completely gray:

Copper coated iron nail

Here’s what the experiment did to the pennies, especially the newer pennies!!

Corroded penny

We also learned that pennies after 1982 are actually zinc that is coated with copper. We could really see this when we took some of the newer pennies out and observed the partially-dissolved, thin copper coating over a darker metal underneath. Copper is so expensive now that it would cost MORE than a penny for each penny to be pure (actually 95%) copper!

Click here for a printable of this experiment.