Turning a Coin to Silver and Gold (Simple Redox Reaction)

This simple experiment will make you understand the redox reaction. This is one of my favorite experiments so I decided to make a post about it.

Things you’ll need: a copper coin (a penny, basically), zinc powder, sodium hydroxide (more than 50%), alcohol lamp, forceps, and a beaker.

1. Pour Sodium Hydroxide into a beaker and pour some zinc dust in it, enough to cover the coin.
2. Put the coin the beaker and wait for a couple hours, I’ll be using my country’s copper coin.
   

   

    

3. Take the coin out with forceps and wash it with water, now you have a silver coin.
4. If you want to continue, do the following steps: Make sure the coin is dry. Heat it up with an alcohol lamp until it’s yellow.
5. Enjoy.

An oxidation-reduction (redox) reaction is a type of chemical reaction that involves a transfer of electrons between two chemicals. A redox reaction is any chemical reaction in which the oxidation number of a molecule, ion, or atom changes by losing or gaining an electron. For example, like this experiment, the zinc transferred its ions to the copper; that’s how the coin turned silver, and that’s why this is a redox reaction. What about turning it to gold? The color of silver and copper are just mixing together when heated and that makes the gold color.