Acetone Dissolves Styrofoam

The inorganic solvent acetone breaks the bindings of Styrofoam, converting the airy material into a slimy mass.

The tiniest components of Styrofoam are extracted from oil, coal, and natural gas. The fossil fuels contain the organic substances of ethylene and benzene, which chemists can combine into styrene. Subsequently, the styrene molecules can be combined into multiple (or poly) long, strong chains known as polystyrene.

Styrofoam is made by blowing vapour and air into small pieces of polystyrene. In the process, airy balls are created, which can be pasted together in large moulds to produce the finished Styrofoam product.

The tiny, white walls of Styrofoam contain lots of tangled polystyrene chains. Van der Waals forces hold the chains together, ensuring that the Styrofoam is stable. But polystyrene chains bind more efficiently to acetone than to other polystyrene chains, so the bindings between the chains break when you immerse the polystyrene into acetone - the result is a liquid that will slowly set.