Heptane
From Freepedia
| General | |
|---|---|
| Molecular formula | C7H16 |
| CAS number | 142-82-5 |
| EC number | 205-563-8 |
| Physical characteristics | |
| Appearance | Colourless liquid |
| Melting point | 182 K (-91 °C) |
| Boiling point | 371 K (98 °C) |
| Vapour density | 3.5 |
| Vapour pressure | 40 mm Hg at 20° Celsius |
| Specific gravity | 0.684 |
| Flash point | -1 °C |
| Explosion limits | 1.1 - 7% |
| Autoignition temperature | 222 °C |
| Spectral data | |
| NMR spectra | 1H NMR spectrum of n-heptane |
Heptane (also known as dipropyl methane, gettysolve-C or heptyl hydride) is an alkane hydrocarbon with the chemical formula CH3(CH2)5CH3. Heptane has nine isomers:
* Heptane * 2-Methylhexane * 3-Methylhexane * 2,2-Dimethylpentane * 2,3-Dimethylpentane * 2,4-Dimethylpentane * 3,3-Dimethylpentane * 3-Ethylpentane * 2,2,3-Trimethylbutane
The isomer n-heptane (straight-chain heptane) has been selected as the zero point of the octane rating scale. It is undesirable in petrol, as it burns explosively, causing engine knocking, as opposed to branched-chain octane isomers, which burn more slowly and give better performance. Its choice for the zero point of the scale was due to the availability of very high purity n-heptane, unmixed with other isomers of heptane or other alkanes, distilled from the resin of Jeffrey Pine. Other sources of heptane and octane, produced from crude oil, contain a mixture of different isomers with greatly differing ratings, so do not give a precise zero point.
External links
| Alkanes | |||||||||||||||||||||||||||||||
|
methane |
| |
ethane |
| |
propane |
| |
butane |
| |
pentane |
| |
hexane | |||||||||||||||||||||
|
heptane |
| |
octane |
| |
nonane |
| |
decane |
| |
undecane |
| |
dodecane |
| ||||||||||||||||||||
|
tridecane |
| |
tetradecane |
| |
pentadecane |
| |
hexadecane |
| |
heptadecane |
| |
octadecane |
| ||||||||||||||||||||
|
nonadecane |
| |
eicosane |
| |
heneicosane |
| |
docosane |
| |
tricosane |
| |
tetracosane |
| ||||||||||||||||||||
|
pentacosane |
| |
hexacosane |
| |
heptacosane |
| |
octacosane |
| |
nonacosane |
| |
triacontane |
| ||||||||||||||||||||
|
hentriacontane |
| |
dotriacontane |
| |
tritriacontane |
| |
tetratriacontane |
| |
pentatriacontane |
| |
hexatriacontane |
| ||||||||||||||||||||
