Alkane
An alkane is a saturated hydrocarbon in which all carbon atoms are connected by single covalent bonds, giving the general formula CₙH₂ⁿ₊₂. Because alkanes contain no double or triple bonds, they are chemically less reactive than other hydrocarbons and are described as "paraffins" in the petroleum industry. They are the principal components of natural gas and crude oil, making them critical energy sources.
Key Formula
CnH(2n+2)
LaTeX: C_nH_{2n+2}
| Symbol | Meaning | Unit |
|---|---|---|
| n | number of carbon atoms | dimensionless (integer ≥1) |
Worked Example
Problem
Write the molecular formula for an alkane with 6 carbon atoms (hexane) and calculate its molar mass.
Solution
Step 1: Apply the formula CnH(2n+2) with n = 6. Step 2: Number of H atoms = 2(6) + 2 = 14. Step 3: Molecular formula = C₆H₁₄. Step 4: Molar mass = 6 × 12.01 + 14 × 1.008 = 72.06 + 14.11 = 86.17 g/mol.
Answer
C₆H₁₄, molar mass = 86.17 g/mol
First Ten Straight-Chain Alkanes
| n | Name | Formula | Molar Mass (g/mol) | Boiling Point (°C) |
|---|---|---|---|---|
| 1 | Methane | CH₄ | 16.04 | −161.5 |
| 2 | Ethane | C₂H₆ | 30.07 | −88.6 |
| 3 | Propane | C₃H₈ | 44.10 | −42.1 |
| 4 | Butane | C₄H₁₀ | 58.12 | −0.5 |
| 5 | Pentane | C₅H₁₂ | 72.15 | 36.1 |
| 6 | Hexane | C₆H₁₄ | 86.18 | 68.7 |
Interactive Tools
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Related Terms
Hydrocarbon
A hydrocarbon is an organic compound consisting entirely of hydrogen and carbon atoms, forming the simplest class of organic molecules. Hydrocarbons are classified by their bonding: saturated (single bonds only) or unsaturated (containing double or triple bonds). They are the primary constituents of fossil fuels and serve as feedstocks for the petrochemical industry.
Alkene
An alkene is an unsaturated hydrocarbon containing at least one carbon–carbon double bond (C=C), with the simplest members following the general formula CₙH₂ⁿ. The double bond consists of a sigma bond and a pi bond, making alkenes more reactive than alkanes and susceptible to addition reactions. Alkenes are industrially vital — ethylene alone is the most-produced organic chemical worldwide, used to make polyethylene plastic.
Organic Chemistry
Organic chemistry is the branch of chemistry that studies the structure, properties, composition, reactions, and synthesis of carbon-containing compounds. Carbon's ability to form four covalent bonds and long chains makes it uniquely suited to build the enormous diversity of organic molecules. This field underpins biochemistry, pharmaceuticals, plastics, and materials science.
From Arabic "al-qili" (the ash, alkali) combined with Latin "-ane" suffix adopted by August Wilhelm von Hofmann in 1866 for saturated hydrocarbons. The suffix "-ane" denotes the saturated single-bond series in IUPAC nomenclature.