Editing Hydrocarbon (section)

==Types==
As defined by the [[International Union of Pure and Applied Chemistry]]'s [[IUPAC nomenclature of organic chemistry|nomenclature of organic chemistry]], hydrocarbons are classified as follows:<ref name=Ullmann>{{cite book |doi=10.1002/14356007.a13_227.pub3 |chapter=Hydrocarbons |title=Ullmann's Encyclopedia of Industrial Chemistry |date=2014 |last1=Schmidt |first1=Roland |last2=Griesbaum |first2=Karl |last3=Behr |first3=Arno |last4=Biedenkapp |first4=Dieter |last5=Voges |first5=Heinz-Werner |last6=Garbe |first6=Dorothea |last7=Paetz |first7=Christian |last8=Collin |first8=Gerd |last9=Mayer |first9=Dieter |last10=Höke |first10=Hartmut |pages=1–74 |isbn=978-3-527-30673-2 }}</ref>
# [[Saturated and unsaturated compounds|Saturated]] hydrocarbons, which are the simplest of the hydrocarbon types. They are composed entirely of [[single bond]]s and are saturated with hydrogen. The formula for [[open-chain compound|acyclic]] saturated hydrocarbons (i.e., [[alkanes]]) is C{{sub|''n''}}H{{sub|2''n''+2}}.<ref name=Silberberg/>{{rp|623}} The most general form of saturated hydrocarbons, (whether linear or branched species, and whether with or without one or more rings) is C{{sub|''n''}}H{{sub|2''n''+2(1-''r'')}}, where ''r'' is the number of rings. Those with exactly one ring are the [[cycloalkanes]]. Saturated hydrocarbons are the basis of [[petroleum fuels]] and may be either linear or branched species. One or more of the hydrogen atoms can be replaced with other atoms, for example chlorine or another halogen: this is called a substitution reaction. An example is the conversion of methane to [[chloroform]] using a [[chlorination reaction]]. Halogenating a hydrocarbon produces something that is not a hydrocarbon. It is a very common and useful process. Hydrocarbons with the same [[molecular formula]] but different [[structural formula]]e are called [[structural isomer]]s.<ref name=Silberberg/>{{rp|625}} As given in the example of [[3-methylhexane]] and its higher [[Homologous series|homologues]], branched hydrocarbons can be [[Chirality (chemistry)|chiral]].<ref name=Silberberg/>{{rp|627}} Chiral saturated hydrocarbons constitute the side chains of [[biomolecule]]s such as [[chlorophyll]] and [[tocopherol]].<ref>{{Cite book |last=Meierhenrich |first=Uwe |url=https://books.google.com/books?id=a2J23yPEaBQC |title=Amino Acids and the Asymmetry of Life: Caught in the Act of Formation |publisher=Springer |year=2008 |isbn=978-3-540-76886-9 |location=Berlin |oclc=288470227}}
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# [[Unsaturated hydrocarbon]]s, which have one or more double or triple bonds between carbon atoms. Those with one or more double bonds are called [[alkene]]s. Those with one [[double bond]] have the formula C{{sub|''n''}}H{{sub|2''n''}} (assuming non-cyclic structures).<ref name=Silberberg/>{{rp|628}} Those containing [[triple bond]]s are called [[alkyne]]. Those with one triple bond have the formula C{{sub|''n''}}H{{sub|2''n''−2}}.<ref name=Silberberg/>{{rp|631}}
# [[Aromatic hydrocarbon]]s, also known as [[arene]]s, which are hydrocarbons that have at least one [[aromatic ring]]. 10% of total nonmethane organic carbon emission are aromatic hydrocarbons from the exhaust of gasoline-powered vehicles.<ref>{{cite web |last1=Barnes |first1=I |title=TROPOSPHERIC CHEMISTRY AND COMPOSITION (Aromatic Hydrocarbons) |url=https://www.sciencedirect.com/topics/earth-and-planetary-sciences/aromatic-hydrocarbon |access-date=26 October 2020}}</ref>

The term 'aliphatic' refers to non-aromatic hydrocarbons. Saturated aliphatic hydrocarbons are sometimes referred to as 'paraffins'. Aliphatic hydrocarbons containing a double bond between carbon atoms are sometimes referred to as 'olefins'.

{| class="wikitable" style="text-align:center"
|+Variations on hydrocarbons based on the number of carbon atoms
!scope="col"|Number of<br />carbon atoms
!scope="col"|[[Alkane]] (single bond)
!scope="col"|[[Alkene]] (double bond)
!scope="col"|[[Alkyne]] (triple bond)
!scope="col"|[[Cycloalkane]]
!scope="col"|[[Alkadiene]]
|-
!scope="row"| 1
|[[Methane]] ||—||—||—||—
|-
!scope="row"| 2
|[[Ethane]] ||[[Ethene]] (ethylene)||[[Acetylene|Ethyne]] (acetylene)||—||—
|-
!scope="row"| 3
|[[Propane]] ||[[Propene]] (propylene)||[[Methylacetylene|Propyne]] (methylacetylene)|| [[Cyclopropane]] || [[Propadiene]] (allene)
|-
!scope="row"| 4
|[[Butane]] ||[[Butene]] (butylene)||[[Butyne]] || [[Cyclobutane]] || [[1,3-Butadiene|Butadiene]]
|-
!scope="row"| 5
|[[Pentane]] ||[[Pentene]] ||[[Pentyne]] || [[Cyclopentane]] || [[Piperylene|Pentadiene]] (piperylene)
|-
!scope="row"| 6
|[[Hexane]] ||[[Hexene]] ||[[Hexyne]] || [[Cyclohexane]] || [[Hexadiene]]
|-
!scope="row"| 7
|[[Heptane]] ||[[Heptene]] ||[[Heptyne]]|| [[Cycloheptane]] || [[Heptadiene]]
|-
!scope="row"| 8
|[[Octane]] ||[[Octene]] ||[[Octyne]] || [[Cyclooctane]] || [[Octadiene]]
|-
!scope="row"| 9
|[[Nonane]] ||[[Nonene]] ||[[Nonyne]] || [[Cyclononane]] || [[Nonadiene]]
|-
!scope="row"| 10
|[[Decane]] ||[[Decene]] ||[[Decyne]] || [[Cyclodecane]] || [[Decadiene]]
|-
!scope="row"| 11
|[[Undecane]] ||[[Undecene]]||[[Undecyne]]|| [[Cycloundecane]] || [[Undecadiene]]
|-
!scope="row"| 12
|[[Dodecane]] ||[[Dodecene]] ||[[Dodecyne]]|| [[Cyclododecane]] || [[Dodecadiene]]
|}