Cetane is the common name for n-hexadecane, a saturated hydrocarbon (alkane) molecule. Its chemical formula is written C16H34. Cetane consists of a chain of 16 carbon atoms, with three hydrogen atoms bonded to the two end carbons, and two hydrogens bonded to each of the middle carbons.
Cetane is often used as a short-hand for cetane number, a measure of the combustibility of diesel fuel. Cetane ignites very easily under compression -- for that reason, it is assigned a cetane number of 100, and serves as a reference for other fuel mixtures.
