In organic chemistry, an alkane, or paraffin (a still-uised historical name that an aa haes ither meanins), is a saturatit hydrocaurbon. In ither wirds, an alkane consists o hydrogen an caurbon atoms arranged in a tree structur in that aw the caurbon-caurbon bonds are single.[1] Alkanes hae the general chemical formula CnH2n+2. The alkanes range in complexity frae the semplest case o methane, CH4 whaur n = 1 (whiles cried the paurent molecule), tae arbitrarily lairge molecules.

Chemical structur o methane, the simplest alkane

Forby this staundart defineetion bi the Internaitional Union o Pure an Applee'd Chemistry, some authors' are still confused bi the term alkane, an uise it tae denote ony saturatit hydrocaurbon, includin thae that are aither monocyclic (i.e. the cycloalkanes) or polycyclic.[2] Sic uissage is clearly in conflict wi the general formula for alkanes (i.e. CnH2n+2), acause cycloalkanes are different frae alkanes, in that thay hae the general chemical formula CnH2n.

In an alkane, ilk caurbon atom is sp3 hybridised wi 4 sigma bonds (aither C-C or C-H), an ilk hydrogen atom is jynt tae ane o the caurbon atoms (sae in a C-H bond). The langest series o airtit caurbon atoms in a molecule is kent as its caurbon skeleton or caurbon backbone. The nummer o caurbon atoms mey be thocht o as the size o the alkane.

Ane group o the heicher alkanes are wauxes, solits at staundart ambient temperatur an pressur (SATP), for that the nummer o caurbons in the caurbon backbane is greater than aboot 17.

Wi thair repeatit -CH2- units, the alkanes constitute a homologous series o organic compoonds in that the members differ in molecular mass bi multiples o 14.03 u (the tot mass o ilk sic methylene-brig unit, that comprises a single caurbon atom o mass 12.01 u an twa hydrogen atoms of mass ~1.01 u ilk).

Alkanes are nae verra reactive an hae little biological activity. Thay can be viewed as molecular trees upon that can be hung the mair active/reactive functional groups o biological molecules.

The alkanes hae twa main commercial soorces: petroleum (crude ile)[3] an naitural gas.

An alkyl group, generally abbreviatit wi the seembol R, is a functional group that, lik an alkane, consists anerly o single-bondit caurbon an hydrogen atoms connectit acyclically—for ensaumple, a methyl or ethyl group.


  1. "Alkane - Definition from the Compendium of Chemical Terminology". Retrieved 14 Juin 2016.
  2. "Alkanes".
  3. Arora, A. (2006). Hydrocarbons (Alkanes, Alkenes And Alkynes). Discovery Publishing House Pvt. Limited. ISBN 9788183561426.