Alkane
Acyclic saturated hydrocarbons forming a homologous series.
Alkanes, also known as paraffins, are a class of organic compounds consisting entirely of hydrogen and carbon atoms arranged in a tree structure with only single carbon–carbon bonds. They are acyclic saturated hydrocarbons with the general formula CnH2n+2, ranging from the simplest methane (CH4) to complex molecules like hexacontane (C60H122). Alkanes are fundamental to organic chemistry, serving as the backbone for more reactive functional groups in biological molecules, and are commercially sourced from petroleum and natural gas.
- field
- Organic chemistry
- known_for
- Acyclic saturated hydrocarbons with general formula CnH2n+2; constitute a homologous series; main commercial sources are petroleum and natural gas
- formula
- CnH2n+2
- simplest_member
- Methane (CH4)
- carbon–carbon_bond_distance
- 1.53 ångströms
Lore & Background
Alkanes are defined by the International Union of Pure and Applied Chemistry (IUPAC) as 'acyclic branched or unbranched hydrocarbons having the general formula CnH2n+2, and therefore consisting entirely of hydrogen atoms and saturated carbon atoms.' However, some sources use the term to denote any saturated hydrocarbon, including monocyclic or polycyclic cycloalkanes, despite their distinct general formula (e.g., cycloalkanes are CnH2n). Each carbon atom in an alkane is sp3-hybridized with four sigma bonds, and the longest series of linked carbon atoms is called the carbon skeleton or backbone. Alkanes with more than about 17 carbon atoms in the backbone are solids at standard ambient temperature and pressure (SATP) and are classified as waxes.
Reader's Guide
Alkanes are significant as the simplest organic compounds, forming a homologous series where members differ by multiples of 14.03 u (the mass of a methylene bridge unit). Their isomerism increases rapidly with carbon number: for example, decane (C10) has 75 isomers, while hexacontane (C60) has over 22 septillion isomers. Branched alkanes are more thermodynamically stable than their linear isomers, as seen with 2,2,3,3-tetramethylbutane being about 1.9 kcal/mol more stable than n-octane. IUPAC nomenclature for alkanes uses Greek numerical prefixes and the suffix '-ane', with the first four names derived from methanol, ether, propionic acid, and butyric acid. Alkanes have limited biological activity, though methane is produced by methanogenic archaea and some long-chain alkanes function as pheromones or protective waxes. Their commercial importance stems from being primary components of petroleum and natural gas.
Did You Know?
- Methane is produced by methanogenic archaea.
- Alkanes with more than about 17 carbon atoms in the backbone are solids at standard ambient temperature and pressure (SATP) and are classified as waxes.
- Branched alkanes are more thermodynamically stable than their linear isomers; for example, 2,2,3,3-tetramethylbutane is about 1.9 kcal/mol more stable than n-octane.
Frequently Asked Questions
Who is Alkane?
Alkane is the name fans give to the entire family of open-chain organic molecules built solely from carbon and hydrogen atoms joined by single bonds. They form a homologous series where each successive member adds one CH₂ unit, stretching from tiny methane up to sprawling hexacontane.
What are Alkane's powers and role?
Alkanes act as the stable structural scaffold onto which more reactive functional groups are grafted in biological and synthetic molecules. Their fully saturated, single-bond framework (C–C distance of 1.53 Å) makes them comparatively inert, giving them a protective 'shield' role inside larger compounds.
How does Alkane's story end?
In the real world, alkanes are harvested primarily from petroleum and natural gas deposits, where they serve as the dominant fuel and feedstock components. Their narrative arc typically concludes in a combustion chamber or a cracking reactor, where the stable chains are broken apart or oxidized to release usable energy.
Why is Alkane important to the franchise?
As the simplest and most abundant class of organic compounds, alkanes provide the foundational carbon-hydrogen architecture upon which virtually all other organic chemistry is constructed. Without this stable backbone, the vast diversity of hydrocarbons and the molecules derived from them would have no structural basis.
What is Alkane's signature formula?
Every member of the series obeys the general formula CₙH₂ₙ₊₂, where n counts the carbon atoms in the chain. This single relationship spans the entire cast, from the one-carbon debutant methane (CH₄) to the sixty-carbon heavyweight hexacontane (C₆₀H₁₂₂).
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