Parent Alkane Names

Parent Alkane Name

The name assigned to an alkane based primarily on the number of carbon atoms in its continuous carbon chain.

1-Carbon Alkane

Methane

Methane

CH₄; the parent alkane containing 1 carbon atom.

2-Carbon Alkane

Ethane

Ethane

C₂H₆; the parent alkane containing 2 carbon atoms.

3-Carbon Alkane

Propane

Propane

C₃H₈; the parent alkane containing 3 carbon atoms.

4-Carbon Alkane

Butane

Butane

C₄H₁₀; the parent alkane containing 4 carbon atoms.

5-Carbon Alkane

Pentane

Pentane

C₅H₁₂; the parent alkane containing 5 carbon atoms.

6-Carbon Alkane

Hexane

Hexane

C₆H₁₄; the parent alkane containing 6 carbon atoms.

7-Carbon Alkane

Heptane

Heptane

C₇H₁₆; the parent alkane containing 7 carbon atoms.

8-Carbon Alkane

Octane

Octane

C₈H₁₈; the parent alkane containing 8 carbon atoms.

9-Carbon Alkane

Nonane

Nonane

C₉H₂₀; the parent alkane containing 9 carbon atoms.

10-Carbon Alkane

Decane

Decane

C₁₀H₂₂; the parent alkane containing 10 carbon atoms.

11-Carbon Alkane

Undecane

Undecane

C₁₁H₂₄; the parent alkane containing 11 carbon atoms.

12-Carbon Alkane

Dodecane

Dodecane

C₁₂H₂₆; the parent alkane containing 12 carbon atoms.

13-Carbon Alkane

Tridecane

Tridecane

C₁₃H₂₈; the parent alkane containing 13 carbon atoms.

20-Carbon Alkane

Icosane

Icosane

C₂₀H₄₂; the parent alkane containing 20 carbon atoms.

30-Carbon Alkane

Triacontane

Triacontane

C₃₀H₆₂; the parent alkane containing 30 carbon atoms.

Alkane Name Ending

-ane

Meaning of the -ane Suffix

Indicates that the parent hydrocarbon is an alkane.

General Formula of Straight-Chain Alkanes

CₙH₂ₙ₊₂

Finding an Alkane Molecular Formula from Carbon Count

Substitute the number of carbon atoms for n in CₙH₂ₙ₊₂.

Finding the Number of Hydrogens in an Alkane

Use 2n + 2, where n is the number of carbon atoms.

Relationship Between Parent Alkane Names and Organic Nomenclature

Parent alkane names provide the carbon-chain roots used as the basis for naming many other organic compounds.

First Four Alkane Names

Methane, ethane, propane, and butane.

Why are the first four alkane names unusual?

Methane, ethane, propane, and butane have historical names rather than names directly derived from Greek numerical prefixes.

Why should the common parent alkane names be memorized?

Recognizing the parent name immediately from the carbon count makes identifying and constructing systematic organic names much easier.