Pentane
Pentane is an organic compound with the chemical formula of C5H12. It is an alkane with five carbon atoms. Usually, "pentane" represents all three isomers (n-pentane, isopentane and neopentane). But in the IUPAC, pentane only represents n-pentane. In the IUPAC, the other two isomers is 2-methylbutane and 2,2-dimethylpropane. Cyclopentane's chemical formula is C5H10, so it is not an isomer of pentane.
| Names | |
|---|---|
| Preferred IUPAC name
Pentane | |
| Other names
Quintane[1]
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| Identifiers | |
| CAS number | |
| PubChem | |
| EC number | 203-692-4 |
| DrugBank | DB03119 |
| MeSH | |
| ChEBI | CHEBI:37830 |
| RTECS number | RZ9450000 |
| SMILES | CCCCC |
| Beilstein Reference | 969132 |
| Gmelin Reference | 1766 |
| Properties | |
| Molecular formula | C5H12 |
| Molar mass | 72.15 g mol-1 |
| Appearance | Colourless liquid |
| Odor | Gasoline-like[2] |
| Density | 0.626 g mL−1; 0.6262 g mL−1 (at 20 °C) |
| Melting point |
Expression error: Unrecognized word "to". °C, 142.7 to 144.1 K, Expression error: Unrecognized word "to". °F |
| Boiling point | |
| Solubility in water | 40 mg L−1 (at 20 °C) |
| log P | 3.255 |
| Vapor pressure | 57.90 kPa (at 20.0 °C) |
| kH | 7.8 nmol Pa−1 kg−1 |
| Acidity (pKa) | ~45 |
| Basicity (pKb) | ~59 |
| λmax | 200 nm |
| -63.05·10−6 cm3/mol | |
| Refractive index (nD) | 1.358 |
| Viscosity | 0.240 mPa·s (at 20 °C) |
| Thermochemistry | |
| Std enthalpy of formation ΔfH |
−174.1–−172.9 kJ mol−1 |
| Std enthalpy of combustion ΔcH |
−3.5095–−3.5085 MJ mol−1 |
| Standard molar entropy S |
263.47 J K−1 mol−1 |
| Specific heat capacity, C | 167.19 J K−1 mol−1 |
| Hazards | |
| NFPA 704 |
4
1
0
|
| Explosive limits | 1.5–7.8%[2] |
| U.S. Permissible exposure limit (PEL) |
TWA 1000 ppm (2950 mg/m3)[2] |
Isomers
| Common name | normal pentane unbranched pentane n-pentane |
isopentane | neopentane |
| IUPAC name | pentane | 2-methylbutane | 2,2-dimethylpropane |
| Molecular diagram |
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| Skeletal diagram |
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Reaction
All isomers of pentane burn with oxygen to make carbon dioxide and water:
- C5H12+8O2->5CO2+6H2O.
References
- ↑ Hofmann, August Wilhelm Von. I. On the action of trichloride of phosphorus on the salts of the aromatic monamines. Proceedings of the Royal Society of London 15 (1 January 1867). p. 54–62. doi:10.1098/rspl.1866.0018. Retrieved 4 April 2018.
- ↑ 2.0 2.1 2.2 NIOSH Pocket Guide to Chemical Hazards. #0486National Institute for Occupational Safety and Health (NIOSH).