Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. This page provides supplementary chemical data on n-pentane. Pentane is an organic compound with the formula C5H12 that is, an alkane with five carbon atoms. The term may refer to any of three structural isomers, or to a mixture of them: in the IUPAC nomenclature, however, pentane means exclusively the n-pentane isomer; the other two being called "methylbutane" and "dimethylpropane". Cyclopentane is not an isomer of pentane.