Cyclohexane. Molecular model of the 'chair' form of the cyclic hydrocarbon cyclohexane. Six carbon atoms (black) are joined by single bonds to form a puckered ring. Each carbon atom has two hydrogen atoms (white) attached. The molecule's chemical formula is C6.H12. The molecule is not fixed in this shape (conformation), but may alter to assume other conformations, since the carbon-carbon bonds can rotate freely. The 'chair' form has one carbon atom above and one below the plane of the other four. 99% of cyclohexane molecules exist in this form under normal conditions. Cyclohexane is used as an intermediate material in the chemical industry when making products such as nylon. It is also used as a solvent and paint remover.