but 2 en

By Admin 20/09/2023 0

From Wikipedia, the không tính phí encyclopedia

Bạn đang xem: but 2 en

But-2-ene

cis

trans

cis

trans

Names
Preferred IUPAC name

But-2-ene

Other names

β-Butylene

Identifiers

CAS Number
  • 107-01-7 check
  • (cis): 590-18-1 check
  • (trans): 624-64-6 check

3D model (JSmol)
  • Interactive image
  • (cis): Interactive image
  • (trans): Interactive image

Beilstein Reference

 1718755 1361341
ChEBI
  • CHEBI:48363 check
  • (cis): CHEBI:48366
  • (trans): CHEBI:48365
ChemSpider
  • 11719 check
  • (cis): 4449912 ☒
  • (trans): 56442 ☒
ECHA InfoCard 100.003.140 Edit this at Wikidata
EC Number
  • 203-452-9

Gmelin Reference

 25196 1140 1141

PubChem CID
  • (cis): 5287573
  • (trans): 62695
RTECS number
  • EM2932000 1718756
UNII
  • S1SK37516R check
  • (cis): L35ORC9C05 check
  • (trans): 017NGL487F check

CompTox Dashboard (EPA)
  • DTXSID1026748 Edit this at Wikidata

InChI

  • InChI=1S/C4H8/c1-3-4-2/h3-4H,1-2H3 check

    Key: IAQRGUVFOMOMEM-UHFFFAOYSA-N check

  • InChI=1/C4H8/c1-3-4-2/h3-4H,1-2H3

    Key: IAQRGUVFOMOMEM-UHFFFAOYAW

  • (cis): InChI=1S/C4H8/c1-3-4-2/h3-4H,1-2H3/b4-3-

    Key: IAQRGUVFOMOMEM-ARJAWSKDSA-N

  • (trans): InChI=1S/C4H8/c1-3-4-2/h3-4H,1-2H3/b4-3+

    Key: IAQRGUVFOMOMEM-ONEGZZNKSA-N

  • C(=CC)C

  • (cis): C/C=C\C

  • (trans): C/C=C/C

Properties

Chemical formula

 C4H8
Molar mass 56.106 g/mol
Density 0.641 g/ml (cis, 3.7 °C)[1]
0.626 g/ml (trans, 0.9 °C)[2]
Melting point −138.9 °C (−218.0 °F; 134.2 K) (cis)[1]
-105.5 °C (trans)[2]
Boiling point 0.8 vĩ đại 3.7 °C (33.4 vĩ đại 38.7 °F; 273.9 vĩ đại 276.8 K) (Z = 3.7 °C)[1]
(E = 0.8 °C)[2]

Magnetic susceptibility (χ)
  • -42.6·10−6 cm3/mol (cis)
  • -43.3·10−6 cm3/mol (trans)
Hazards[3]
GHS labelling:

Pictograms

 Flam. Gas 1Press. Gas

Signal word

 Danger

Hazard statements

 H220

Precautionary statements

 P210, P377, P381, P403
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 4: Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily. Flash point below 23 °C (73 °F). E.g. propaneInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code

1

4

Flash point −72 °C (−98 °F; 201 K)[1][2]

Autoignition
temperature

 325 °C (617 °F; 598 K)[1][2]
Related compounds

Related butenes

 1-Butene
cis-2-Butene
trans-2-Butene
Isobutene

Related compounds

 Butane
Butyne

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

☒ verify (what is check☒ ?)

Infobox references

But-2-ene () 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 geometric isomers cis-but-2-ene ((Z)-but-2-ene) and trans-but-2-ene ((E)-but-2-ene).

It is a petrochemical, produced by the catalytic cracking of crude oil or the dimerization of ethylene. Its main uses are in the production of gasoline (petrol) and butadiene,[4] although some but-2-ene is also used vĩ đại produce the solvent butanone via hydration vĩ đại 2-butanol followed by oxidation.

The two isomers are extremely difficult vĩ đại separate by distillation because of the proximity of their boiling points (~4 °C for cis and ~1 °C for trans[5]). However, separation is unnecessary in most industrial settings, as both isomers behave similarly in most of the desired reactions. A typical industrial but-2-ene mixture is 70% (Z)-but-2-ene (cis-isomer) and 30% (E)-but-2-ene (trans-isomer). Butane and but-1-ene are common impurities, present at 1% or more in industrial mixtures, which also contain smaller amounts of isobutene, butadiene and butyne.[4]

Xem thêm: bài 24 trang 80 sgk toán 8 tập 1

References[edit]

  1. ^ a b c d e Record in the GESTIS Substance Database of the Institute for Occupational Safety and Health
  2. ^ a b c d e Record in the GESTIS Substance Database of the Institute for Occupational Safety and Health
  3. ^ cis-2-Butene, International Chemical Safety Card 0397, Geneva: International Programme on Chemical Safety, March 1996. trans-2-Butene, International Chemical Safety Card 0398, Geneva: International Programme on Chemical Safety, March 1996.
  4. ^ a b 2-Butene (PDF), SIDS Initial Assessment Report, Geneva: United Nations Environment Programme, February 1995.
  5. ^ Chemical Safety Information from Intergovernmental Organizations Archived December 9, 2009, at the Wayback Machine

External links[edit]

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