Science at Home

Science at Home: Copper Plating

This month we’re exploring chemistry and are going to use household things to change the color of a paperclip.

First a little background: Pennies become dull over time due when the copper on the surface of the coin reacts with oxygen in the air, creating copper dioxide. Vinegar is an acid so when you place the pennies in a vinegar/salt solution, it begins to dissolve the copper dioxide. The copper that is dissolved in the vinegar and salt is positively charged.

When we place a paperclip in this salt and vinegar solution, it dissolves some of the iron (or iron oxide) on the paperclip’s surface. This leaves behind a negative charge. Because opposite charges attract, this positively charged copper ion is attracted to the paperclip and coats the surface of the paperclip!

Another cool side effect of this experiment? Really clean pennies.

Here’s what you need:

  • 5-10 dull pennies
  • ¼ cup of white vinegar
  • 1 tablespoon of salt
  • Non-metal cup
  • Steel paper clips


The experiment:

  1. Mix the vinegar and salt in the cup.
  2. Place the pennies into the mixed vinegar and salt and let sit for about 5 minutes.
  3. While the pennies and vinegar mix is sitting, bend your paperclip into a fun shape.
  4. Place your paperclip into the vinegar, salt and penny mixture.
  5. Check back in on your paperclip in about an hour. It should be covered in copper!

    Enjoyed changing the color of your paperclip? Share your pictures with us at #smwv!

    Developed by Hannah Weiss and Koren Smith