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.
Pentane | |
---|---|
Pentane | |
Other names | Quintane[1] |
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 |
|
Explosive limits | 1.5–7.8%[2] |
U.S. Permissible exposure limit (PEL) |
TWA 1000 ppm (2950 mg/m3)[2] |
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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 |
Reaction
All isomers of pentane burn with oxygen to make carbon dioxide and water:
- C5H12+8O2->5CO2+6H2O.
References
- ↑ Hofmann, August Wilhelm Von (1 January 1867). "I. On the action of trichloride of phosphorus on the salts of the aromatic monamines". Proceedings of the Royal Society of London. 15: 54–62. doi:10.1098/rspl.1866.0018. S2CID 98496840. Retrieved 4 April 2018 – via rspl.royalsocietypublishing.org.
- ↑ 2.0 2.1 2.2 NIOSH Pocket Guide to Chemical Hazards. "#0486". National Institute for Occupational Safety and Health (NIOSH).