2-Butene

2-Butene
IUPAC name But-2-ene
Other names β-Butylene
Identifiers
CAS number	107-01-7 Y
ChemSpider	11719 Y
UNII	S1SK37516R Y
EC-number	203-452-9
ChEBI	CHEBI:48363 Y
RTECS number	EM2932000
Jmol-3D images	Image 1
SMILES C(=CC)C
InChI InChI=1S/C4H8/c1-3-4-2/h3-4H,1-2H3 Y Key: IAQRGUVFOMOMEM-UHFFFAOYSA-N Y InChI=1/C4H8/c1-3-4-2/h3-4H,1-2H3 Key: IAQRGUVFOMOMEM-UHFFFAOYAW
Properties
Molecular formula	C4H8
Molar mass	56.106 g/mol
Melting point	-139°C
Boiling point	4 °C, 277 K, 39 °F
Hazards[1]
GHS pictograms	Template:GHS04
GHS signal word	DANGER
GHS hazard statements	H220
GHS precautionary statements	P210, P377, P381, P403
EU Index	601-012-00-4
EU classification	Extremely flammable (F+)
R-phrases	R12
S-phrases	(S2) S9 S16 S33
NFPA 704	4 1 0
Flash point	flammable gas
Autoignition temperature	324 °C (615 °F)
Related compounds
Related butenes	1-Butene cis-2-Butene trans-2-Butene Isobutene
Related compounds	Butane Butyne
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

2-Butene is an acyclic alkene with four carbon atoms. It is the simplest alkene exhibiting cis/trans-isomerism (also known as (E/Z)-isomerism); that is, it exists as two geometrical isomers cis-2-butene ((Z)-2-butene), shown at the right, and trans-2-butene ((E)-2-butene), not shown.

It is a petrochemical, produced by the catalytic cracking of crude oil. Its main uses are in the production of gasoline (petrol) and butadiene,^[2] although some 2-butene is also used to produce the solvent butanone via hydration to 2-butanol followed by oxidation.

The two isomers are extremely difficult to separate by distillation because of the proximity of their boiling points (4 °C for cis and 1 °C for trans^[3]). The more elongated trans-molecule which has a tougher job to get its tail free from the liquid has the higher boiling point, the more rounded cis isomer escapes easier, thus having a lower boiling point. However, separation is unnecessary in most industrial settings, as both isomers behave similarly in most of the desired reactions. A typical industrial 2-butene mixture is 70% (Z)-2-butene (cis-isomer) and 30% (E)-2-butene (trans-isomer). Butane and 1-butene are common impurities, present at 1% or more in industrial mixtures, which also contain smaller amounts of isobutene, butadiene and butyne.^[2]

References

1. ^ cis-2-Butene, International Chemical Safety Card 0397, Geneva: International Programme on Chemical Safety, March 1996, http://www.inchem.org/documents/icsc/icsc/eics0397.htm . trans-2-Butene, International Chemical Safety Card 0398, Geneva: International Programme on Chemical Safety, March 1996, http://www.inchem.org/documents/icsc/icsc/eics0398.htm .
2. ^ ^{a b} 2-Butene, SIDS Initial Assessment Report, Geneva: United Nations Environment Programme, February 1995, http://www.inchem.org/documents/sids/sids/107017.pdf .
3. ^ Chemical Safety Information from Intergovernmental Organizations

External links

• SIDS Initial Assessment Report for 2-Butene from the Organisation for Economic Co-operation and Development (OECD)

This article about a hydrocarbon is a stub. You can help Wikipedia by expanding it.v · Categories: Alkenes Hydrocarbon stubs Wikimedia Foundation. 2010. Игры ⚽ Нужно решить контрольную? Hawaii tropical moist forests The Green Mile Look at other dictionaries: Butene — (auch Butylene) sind eine Gruppe von vier isomeren Kohlenwasserstoffen mit der allgemeinen Summenformel C4H8, die über eine C–C Doppelbindung verfügen. Sie zählen damit zu den Alkenen. Zwei der Isomere unterscheiden sich durch cis trans Isomerie …   Deutsch Wikipedia Butene — Butène Le butène (ou butylène) C4H8 est un gaz incolore et sans odeur, deux fois plus lourd que l air, soluble dans les solvants organiques polaires (hydrocarbures). Il s enflamme à 440 °C. Sommaire 1 Isoméres 2 Obtention 3 Utilisations …   Wikipédia en Français Butene — Butene, also known as butylene, is an alkene with the formula C4H8. It is a colourless gas that is present in crude oil as a minor constituent in quantities that are too small for viable extraction. It is therefore obtained by catalytic cracking… …   Wikipedia butène — [ bytɛn ] n. m. • 1845; du rad. de but(ylique) et suff. chim. ène ♦ Chim. Hydrocarbure éthylénique C4 H8. ⇒vieilli butylène. ● butène nom masculin Hydrocarbure éthylénique, C4H8, dont il existe trois isomères, le butène 1 et les butènes 2 cis et… …   Encyclopédie Universelle Butene — Butene,   Singular Buten das, s, Butylene, ungesättigte Kohlenwasserstoffe aus der Gruppe der Alkene, die sich von den Butanen ableiten. Sie treten meist als Gemisch der drei Isomeren 1 Buten, 2 Buten und Isobuten …   Universal-Lexikon butene — utene n. any of three isomeric singly unsaturated hydrocarbons {C4H8}; all are used in making synthetic rubbers; called also {butylene}. [WordNet 1.5] …   The Collaborative International Dictionary of English butene — [byo͞o′tēn΄] n. BUTYLENE …   English World dictionary Butène — Le butène (ou butylène) C4H8 est un gaz incolore et sans odeur, deux fois plus lourd que l air, soluble dans les solvants organiques polaires (hydrocarbures). Il s enflamme à 440 °C. Sommaire 1 Isomères 2 Obtention 3 Utilisations …   Wikipédia en Français butene — /byooh teen/, n. Chem. butylene (def. 1). [BUT(YL) + ENE] * * * ▪ chemical compound also called  Butylene,         any of four isomeric compounds belonging to the series of olefinic hydrocarbons. The chemical formula is C4H8. The isomeric forms… …   Universalium butene — noun any of three isomeric hydrocarbons C4H8; all used in making synthetic rubbers • Syn: ↑butylene • Hypernyms: ↑gas • Hyponyms: ↑isobutylene, ↑polybutylene, ↑polybutene * * * ˈbyüd.ēn …   Useful english dictionary butene — Butylene Bu ty*lene, n. [From {Butyl}.] 1. (Chem.) Any one of three metameric hydrocarbons, {C4H8}, of the ethylene series. They are gaseous or easily liquefiable; called also {butene}. [1913 Webster] 2. the hypothetical divalent radical { (CH2)4 …   The Collaborative International Dictionary of English 18+ © Academic, 2000-2024 Contact us: Technical Support, Advertising Dictionaries export, created on PHP, Joomla, Drupal, WordPress, MODx. Mark and share Search through all dictionaries Translate… Search Internet Share the article and excerpts Direct link … Do a right-click on the link above and select “Copy Link”