Butane
| Butane | | Skeletal structure of a butane molecule |
| 3D model of a butane molecule |
|
| General |
|---|
| Molecular formula | C4H10 |
| SMILES | CCCC |
| Molar mass | 58.08 g/mol |
| Appearance | colorless gas |
| CAS number | [106-97-8] |
| Properties |
|---|
| Density and phase | 2.52 g/l, gas (15 °C, 1 atm) |
| Solubility in water | 6.1 mg/100 ml (20 °C) |
>| Melting point−138.3 °C (134.9 K) |
| Boiling point | −0.5 °C (272.7 K) |
| Hazards |
|---|
| MSDS | External MSDS |
| EU classification | Highly flammable (F+) |
| NFPA 704 | |
| R-phrases | |
| S-phrases | , , |
| Flash point | −60 °C |
| Autoignition temperature | 287 °C |
| Explosive limits | 1.8–8.4% |
| Supplementary data page |
|---|
Structure and
properties | n, εr, etc. |
Thermodynamic
data | Phase behaviour
Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
| Related compounds |
|---|
| Related alkanes | Propane
Pentane |
| Related compounds | Isobutane |
Except where noted otherwise, data are given for
materials in their standard state (at 25 °C, 100 kPa)
Infobox disclaimer and references |
|
Butane, also called
n-butane, is the unbranched
alkane with four
carbon atoms, CH
3CH
2CH
2CH
3.
Butane is also used as a collective term for
n-butane together with its only other isomer,
isobutane (also called methylpropane), CH(CH
3)
3.
Butanes are highly flammable, colorless, easily
liquefied gases. The name butane was derived by back-formation from the name of
butyric acid.
|
Structures of the two isomers of butane |
When oxygen is plentiful, butane burns to form carbon dioxide and water vapor:When oxygen is limited, carbon (soot) or carbon monoxide may also be formed.
n-Butane is the feedstock for duPont's process for the preparation of
maleic anhydride. The catalyst for this process has the approximate formula ::CH
3CH
2CH
2CH
3 + 3.5 O
2 â†' C
2H
2(CO)
2O + 4 H
2O
Butane, like all hydrocarbons, undergoes
free radical chlorination to give both 1-chloro- and 2-chlorobutanes, as well as more highly chlorinated derivatives. The relative rates of the chlorination is partially explained by the differing
bond dissociation energies, 425 and 411
kJ/mol for the two types of C-H bonds. The two central carbon atoms have the slightly weaker C-H bonds.
Butane gas is sold bottled as a fuel for cooking and camping, in which case it is referred to commercially as
LPG. It is also used as a petrol component, as a feedstock for the production of base petrochemicals in steam cracking, as fuel for
cigarette lighters and as a
propellant in
aerosol sprays. Despite its flammability, very pure forms of butane are also occasionally used as a
refrigerant in automobiles that are set up to use
R-12, because R-12 is an
ozone depleting
halomethane.
*
Butane bottle*
Volatile substance abuse*
Camping Gaz*
Calor gas
*Bond dissociation energies: Senosiain, J. P.; Han, J. H.; Musgrave, C. B.; Golden, D. M.
Faraday Discussions 2001,
119, 173-189.
*Coulston, G. W.; Bare, S. R.; Kung, H.; Birkeland, K.; Bethke, G. K.; Harlow, R.; Herron, N.; Lee, P. L. "The Kinetic Significance of V
5+ in
n-Butane Oxidation Catalyzed by Vanadium Phosphates"
Science 1997,
275, pp. 191 - 193.
*
World LP Gas Association (WLPGA)*
LP Gas Association: Propane and Butane in the UK*
International Chemical Safety Card 0232*
NIOSH Pocket Guide to Chemical Hazards*
n-Butane,
Molecule of the Month.
*
Molview from bluerhinos.co.uk See Butane in 3D
*
Computational Chemistry Wiki*
Data from Air Liquide*
Butane bottle information.
