n-Heptane is the straight-chain alkane with the chemical formula H3C(CH2)5CH3 or C7H16. Heptane (and its many isomers) is widely applied in laboratories as a non-polar solvent. As a liquid, it is ideal for transport and storage. In the grease spot test, heptane is used to dissolve an oil spot to show the previous presence of organic compounds on a stained paper. Heptane is commercially available as mixed isomers for use in paints and coatings