The chemical formula of butane is C4H10. This four-carbon compound is classified as an alkane, so its structure follows the generic formula CnH2n+2. The structure of butane is written as follows: CH3-CH2-CH2-CH3.
Butane, also called n-butane, has a constitutional isomer, which is a compound with the same molecular formula but a different structure, called isobutane. In contrast to butane, this branched isomer features three CH3 groups and a CH group, all of these atoms adding up to the same C4H10 molecular formula.
Butane and isobutane are colorless and odorless gases. They are used as aerosol propellants and are included in the formulation of several cosmetic products, such as hair conditioner and shaving cream, as indicated by Cosmeticsinfo.