Alkanes
Alkanes are hydrocarbons (only carbon and hydrogen) in which every bond between carbons is single. It's the most basic organic function — the carbon skeleton of every other function is, at its core, an alkane backbone with a functional group attached.
General formula
Naming rule
Name = numerical prefix (meth, eth, prop...) + suffix -ane. Branched chains take the name of the alkyl substituent(s) as a prefix, with the lowest possible locant.
How to name it with IUPAC
Use this sequence to move from the structure to the systematic name:
- Choose the longest continuous carbon chain.
- Number the chain to give substituents the lowest locants and use the -ane suffix.
- 2-methylpropane = methyl on carbon 2 + propane as the parent chain.
Examples
| Name | Formula |
|---|---|
| Methane | CH₄ |
| Ethane | C₂H₆ |
| Propane | C₃H₈ |
| Butane | C₄H₁₀ |
| 2-methylpropane | C₄H₁₀ branched |
Visual examples
See how the functional group appears inside the chain. Compare the drawings with the formulas in the table to practice visual recognition.
Chemical reading
Single bonds make alkanes relatively nonpolar; larger chains boil higher because dispersion forces increase.
Properties and applications
Complete combustion gives CO₂ and H₂O. Methane, propane, octane, and paraffin waxes are practical examples.
- No C=C or C≡C is present: CH₃CH₂CH₂CH₃ is butane, while (CH₃)₃CH is 2-methylpropane.
- Compare polarity, chain size, and hydrogen bonding before predicting physical properties.