Coleman fuel is a mixture of cyclohexane, nonane, octane, heptane, and pentane. Hence, pentane, CH; hexane, CH; heptane, CH; octane, CH; etc. It is composed of heptane, cellulose, methyl rhenium trioxide, butylated hydroxytoluene, and polyphenol oxidase. Aqueous bromine may be distinguished from aqueous iodine by its appearance after extraction into heptane. The index is measured by determining the fraction of the polymer insoluble in boiling heptane. The density and boiling are the lowest of the isomers of heptane. The dielectric constant is 1.915, the lowest of the heptane isomers. These products are, for polyethylene, ethylene, propylene, isobutylene, 1-hexene and heptane. However, iodine turns purple when dissolved in heptane, whereas the bromine solution remains brown. It is one of the isomers of heptane. A lower density of liquid is found in 2-Methylhexane than heptane. Heptane (and its many isomers) is widely used in laboratories as a non-polar solvent. Therefore, 2-methylhexane has a lower Autoignition temperature and flash point when compared to heptane. Heptane is an alkane of seven carbon atoms, with the chemical formula CH.