What you need:
- Clear container (glass or plastic will work)
- Safety Glasses
- A well ventalated room
- Gather all your materials and set up in a well ventilated room
- Put on your safety glasses & gloves
- Fill your container about 1/4 the way or less with acetone
- Place Styrofoam into the container
- Push down pieces as needed
- Watch results
Acetone is a solvent that breaks down Styrofoam, which results in the Styrofoam dissolving in Acetone similar to how sugar does in water.
Styrofoam is a polystyrene that has been pumped with air. Things like Styrofoam packaging and cups are actually actually over 90% air. The other 10 percent or less is polystyrene, which is versatile plastic.
Acetone is an organic compound with the formula (CH3)2CO. Acetone dissolves the bonds that hold together Styrofoam. As the bonds break up, air is released. Since the majority of Styrofoam is air, with the air gone, it takes up far less space.
The bubbles you see when the Styrofoam meets the acetone is actually air escaping as the bonds holding it together are broken up. Even though it looks like the Styrofoam has completely disappeared, the polystyrene molecules that are left mix in with acetone solution, similar to how sugar or salt can mix with water.
Since Styrofoam is mostly air, it is a good insulator. That’s why it will commonly be used as a cup to keep drinks warm.
Since Styrofoam cannot be recycled on your curbside, doing an experiment like this is not only fun, but can help out the environment.