Acetone, or propanone, is an organic compound with the chemical formula (CH3)2CO. This clear, mobile, easy-to-burn liquid is the simplest example of the ketones. Acetone can be mixed with water. It is an important solvent, often to clean things in the laboratory. Common uses of acetone in the home are as the active ingredient in nail polish remover and as paint thinner. It is a common building block in organic chemistry.