Editing Heptane (section)

==Uses==
Heptane and its many isomers are widely used in [[Laboratory|laboratories]] as a non-polar [[solvent]].<ref>{{cite arXiv |eprint=2410.09901 |last1=Fang |first1=Shen |last2=Zhang |first2=Siyi |last3=Li |first3=Zeyu |last4=Fu |first4=Qingfei |last5=Zhou |first5=Chong-Wen |last6=Hana |first6=Wang |last7=Yang |first7=Lijun |title=A data-driven sparse learning approach to reduce chemical reaction mechanisms |date=2024 |class=physics.chem-ph }}</ref> It is often preferred to [[hexane]] due to heptane being comparatively less toxic and less volatile.<ref>{{Cite web |title=Differences Between Heptane and Hexane - Solvent Extractors |url=https://ecolink.com/info/difference-between-hexane-and-heptane/?srsltid=AfmBOop2HAJ_5JY4ZT7kT4qxej1mM8gfJFdsUHg-2Yg0ff-WxKcSyT5n |access-date=2025-03-30 |website=ecolink.com}}</ref> 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. This is done by shaking the stained paper in a heptane solution for about half a minute.{{Citation needed|date=July 2009}}

Aqueous [[bromine]] may be distinguished from aqueous [[iodine]] by its appearance after [[Extraction (chemistry)|extraction]] into heptane. In water, both bromine and iodine appear [[brown]].  However, iodine turns [[purple]] when dissolved in heptane, whereas the bromine solution remains brown.

Heptane is commercially available as both pure and mixed isomers for use in paints and coatings, as the [[rubber cement]] solvent "Bestine",<ref>{{Cite web |date=27 June 2022 |title=BESTINE SOLVENT & THINNER OSHA SDS |url=https://www.speedballart.com/wp-content/uploads/2022/08/Bestine-OSHA-SDS-EN.pdf |url-status=live |archive-url=https://web.archive.org/web/20230426012051/https://www.speedballart.com/wp-content/uploads/2022/08/Bestine-OSHA-SDS-EN.pdf |archive-date=26 April 2023 |access-date=24 December 2024 |publisher=Speedball Art Products Co.}}</ref> the outdoor stove fuel "Powerfuel" by Primus, as pure ''n''-heptane for research and development and pharmaceutical manufacturing and as a minor component of [[gasoline]] (petrol). On average, gasoline is about 1% heptane.<ref>{{cite journal |last1=Conner |first1=Teri L. |last2=Lonneman |first2=William A. |last3=Seila |first3=Robert L. |title=Transportation-Related Volatile Hydrocarbon Source Profiles Measured in Atlanta |journal=Journal of the Air & Waste Management Association |date=1 May 1995 |volume=45 |issue=5 |pages=383–394 |doi=10.1080/10473289.1995.10467370|doi-access=free |bibcode=1995JAWMA..45..383C }}</ref><ref>{{cite journal |last1=Schauer |first1=James J. |last2=Kleeman |first2=Michael J. |last3=Cass |first3=Glen R. |last4=Simoneit |first4=Bernd R. T. |title=Measurement of Emissions from Air Pollution Sources. 5. C 1 −C 32 Organic Compounds from Gasoline-Powered Motor Vehicles |journal=Environmental Science & Technology |date=1 March 2002 |volume=36 |issue=6 |pages=1169–1180 |doi=10.1021/es0108077|pmid=11944666 |bibcode=2002EnST...36.1169S }}</ref>

Heptane is also used as an [[adhesive remover]] by [[Stamp collecting|stamp collectors]]. Since 1974, the [[United States Postal Service]] has issued [[self-adhesive stamp]]s that some collectors find difficult to separate from envelopes via the traditional method of soaking in water. Heptane-based products like Bestine, as well as [[limonene]]-based products, have become popular solvents for removing stamps more easily.<ref>{{cite web |last1=Butler |first1=Peter |title=It's Like Magic: Removing Self-Adhesive Stamps from Paper |url=https://classic.stamps.org/userfiles/file/HowTos/RemovingSelfAdhesives-Part1.pdf |publisher=American Philatelic Society |access-date=15 June 2020}}</ref>

===Octane rating scale===
''n''-Heptane is defined as the zero point of the [[octane rating]] scale. It is a lighter component in [[gasoline]] and burns more [[explosive]]ly, causing [[engine]] pre-ignition ([[engine knocking|knocking]]) in its pure form, as opposed to [[octane]] isomers, which burn more slowly and give less knocking. It was originally chosen as the zero point of the scale because of the availability of very high purity ''n''-heptane, unmixed with other isomers of heptane or other alkanes, distilled from the [[resin]] of [[Jeffrey pine]] and from the fruit of ''[[Pittosporum resiniferum]]''. Other sources of heptane and octane, produced from [[crude oil]], contain a mixture of different isomers with greatly differing ratings, and do not give as precise a zero point.