Butane

From Infogalactic: the planetary knowledge core
Jump to: navigation, search
Butane
Skeletal formula of butane with all carbon and hydrogen atoms shown
Ball-and-stick model of the butane molecule
Space-filling model of the butane molecule
Names
IUPAC name
Butane[2]
Other names
Butyl hydride[1]
Methylethylmethane[1]
Identifiers
106-97-8 YesY
969129
ChEBI CHEBI:37808 YesY
ChEMBL ChEMBL134702 YesY
ChemSpider 7555 YesY
EC Number 203-448-7
1148
Jmol 3D model Interactive image
KEGG D03186 YesY
MeSH butane
PubChem 7843
RTECS number EJ4200000
UNII 6LV4FOR43R YesY
UN number 1011
  • InChI=1S/C4H10/c1-3-4-2/h3-4H2,1-2H3 YesY
    Key: IJDNQMDRQITEOD-UHFFFAOYSA-N YesY
  • CCCC
Properties
C4H10
Molar mass 58.12 g·mol−1
Appearance Colorless gas
Odor Gasoline-like or natural gas-like[1]
Density 2.48 kg/m3 (at 15 °C (59 °F))
Melting point −140 to −134 °C; −220 to −209 °F; 133 to 139 K
Boiling point −1 to 1 °C; 30 to 34 °F; 272 to 274 K
61 mg L−1 (at 20 °C (68 °F))
log P 2.745
Vapor pressure ~170 kPa at 283 K [3]
11 nmol Pa−1 kg−1
Thermochemistry
98.49 J K−1 mol−1
−126.3–−124.9 kJ mol−1
−2.8781–−2.8769 MJ mol−1
Vapor pressure {{{value}}}
Related compounds
Related alkanes
Related compounds
Perfluorobutane
Supplementary data page
Refractive index (n),
Dielectric constantr), etc.
Thermodynamic
data
Phase behaviour
solid–liquid–gas
UV, IR, NMR, MS
YesY verify (what is YesYN ?)
Infobox references

Butane (/ˈbjuːtn/) is an organic compound with the formula C4H10 that is an alkane with four carbon atoms. Butane is a gas at room temperature and atmospheric pressure. The term may refer to either of two structural isomers, n-butane or isobutane (or "methylpropane"), or to a mixture of these isomers. In the IUPAC nomenclature, however, "butane" refers only to the n-butane isomer (which is the isomer with the unbranched structure). Butanes are highly flammable, colorless, easily liquefied gases. The name butane comes from the roots but- (from butyric acid) and -ane.

Isomers

Common name normal butane
unbranched butane
n-butane
isobutane
i-butane
IUPAC name butane 2-methylpropane
Molecular
diagram
Butan Lewis.svg Isobutane 1.svg
Skeletal
diagram
Butane simple.svg I-Butane-2D-Skeletal.svg

Rotation about the central C−C bond produces two different conformations (trans and gauche) for n-butane.[4]

Reactions

<templatestyles src="Stack/styles.css"/>

Spectrum of the blue flame from a butane torch showing CH molecular radical band emission and C2 Swan bands

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.

When there is sufficient oxygen:

2 C4H10 + 13 O2 → 8 CO2 + 10 H2O

When oxygen is limited:

2 C4H10 + 9 O2 → 8 CO + 10 H2O

The maximum adiabatic flame temperature of butane with air is 2,243 K (1,970 °C; 3,578 °F).

n-Butane is the feedstock for DuPont's catalytic process for the preparation of maleic anhydride:

2 CH3CH2CH2CH3 + 7 O2 → 2 C2H2(CO)2O + 8 H2O

n-Butane, like all hydrocarbons, undergoes free radical chlorination providing 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.

Uses

Normal butane can be used for gasoline blending, as a fuel gas, either alone or in a mixture with propane, and as a feedstock for the manufacture of ethylene and butadiene, a key ingredient of synthetic rubber. Isobutane is primarily used by refineries to enhance (increase) the octane number of motor gasoline.[5][6][7][8]

When blended with propane and other hydrocarbons, it may be referred to commercially as LPG, for liquefied petroleum gas. It is 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 such as deodorants.[9]

Very pure forms of butane, especially isobutane, can be used as refrigerants and have largely replaced the ozone-layer-depleting halomethanes, for instance in household refrigerators and freezers. The system operating pressure for butane is lower than for the halomethanes, such as R-12, so R-12 systems such as in automotive air conditioning systems, when converted to butane will not function optimally.

Butane cylinder for use in a camping stove.

Butane is also used as lighter fuel for a common lighter or butane torch and is sold bottled as a fuel for cooking and camping.[10] In this form it is often mixed with small amounts of hydrogen sulfide and mercaptans which will give the unburned gas an offensive smell easily detected by the human nose. In this way, butane leaks can easily be identified. Both hydrogen sulfide and mercaptans, while considered poisons, have low boiling points and quickly vaporize when not under pressure. Most commercially available butane also contains a certain amount of contaminant oil which can be removed through filtration but which will otherwise leave a deposit at the point of ignition and may eventually block the uniform flow of gas.

Cordless hair irons are usually powered by butane cartridges.[11]

Effects and health issues

Inhalation of butane can cause euphoria, drowsiness, narcosis, asphyxia, cardiac arrhythmia, fluctuations in blood pressure and temporary memory loss, when abused directly from a highly pressurized container, and can result in death from asphyxiation and ventricular fibrillation. Butane is the most commonly misused volatile substance in the UK, and was the cause of 52% of solvent related deaths in 2000.[12] By spraying butane directly into the throat, the jet of fluid can cool rapidly to −20 °C (−4 °F) by expansion, causing prolonged laryngospasm.[13] "Sudden sniffer's death" syndrome, first described by Bass in 1970,[14] is the most common single cause of solvent related death, resulting in 55% of known fatal cases.[13]

A small amount of nitrogen dioxide, a toxic gas, results from burning butane gas, along with any combustion in the earth's atmosphere, and represents a human health hazard from home heaters and stoves.[15]

See also

References

  1. 1.0 1.1 1.2 Cite error: Invalid <ref> tag; no text was provided for refs named PGCH
  2. CID 7843 from PubChem
  3. Lua error in package.lua at line 80: module 'strict' not found.
  4. Lua error in package.lua at line 80: module 'strict' not found.
  5. MarkWest Energy Partners, L.P. Form 10-K. Sec.gov
  6. Copano Energy, L.L.C. Form 10-K. Sec.gov. Retrieved on 2012-12-03.
  7. Targa Resources Partners LP Form10-k. Sec.gov. Retrieved on 2012-12-03.
  8. Crosstex Energy, L.P. FORM 10-K. Sec.gov
  9. A Primer on Gasoline Blending. An EPRINC Briefing Memorandum
  10. Lua error in package.lua at line 80: module 'strict' not found.
  11. FAA: Hazardous Materials p. 4
  12. Lua error in package.lua at line 80: module 'strict' not found.
  13. 13.0 13.1 Lua error in package.lua at line 80: module 'strict' not found.
  14. Lua error in package.lua at line 80: module 'strict' not found.
  15. Lua error in package.lua at line 80: module 'strict' not found.

External links