How to make a spooky Halloween keychain
DIY Adorable and spooky keychain
Only under adult supervision.
Equipment and reagents
- copperized plate;
- 16g table salt;
- 6g copper(II) sulfate;
- 40mL hot water;
Polish a copperized plate with sandpaper. Apply a stencil to the plate and place it in a cup. Add 6g copper(II) sulfate and 16g sodium chloride. Add 40mL hot water and stir the resulting mixture. 10 minutes later, retrieve the plate. The copper on the plate dissolved! Rinse with water and remove the sticker – the image stays put!
The surface of the plate is covered with oils, dust, and dirt particles. We use sandpaper to remove them, exposing the metallic copper and making it more reactive. The copper sulfate dissolves in water to yield copper(II) Cu²⁺ and sulfate ions. Cu²⁺ has two fewer electrons than the neutral copper Cu⁰ on the copper plate. When these two versions of copper meet each other, electrons from the metallic copper Cu⁰ transfer to the copper(II) ions Cu²⁺, and they both turn into copper(I) Cu¹⁺ ions. As a result, the metal dissolves off the polymer plate everywhere except the area protected with the stencil. Looks cool, right?
And did you know? A similar experiment is included in the “Etching and Plating” set from the MEL Chemistry subscription!