Acetone. Computer model of a molecule of acetone. Also known as propan-2-one, this chemical is a sweet-smelling colourless liquid which is widely used in industry and laboratories as a solvent. It is also the main component of nail varnish remover. The molecule's chemical formula is C3.H6.O. The atoms are represented as colour-coded spheres in this space-filled model: carbon (blue), hydrogen (yellow), and oxygen (red).