Ethane is an organic chemical compound with chemical formula C2H6. At standard temperature and pressure, ethane is a colorless, odorless gas. Ethane is isolated on an industrial scale from natural gas, and as a byproduct of petroleum refining. Its chief use is as petrochemical feedstock for ethylene production.
Solid ethane exists in several modifications. On cooling under normal pressure the first modification to appear is a plastic crystal, crystallizing in the cubic system. Here the positions of the hydrogen atoms are not fixed; the molecules may rotate freely around their long axis. Cooling this ethane I below ca. 89.9 K changes it to monoclinic metastable ethane II