Ethene

Overview

Ethylene

The alkene monomer used to make polyethylene, including LDPE.

The carbon–carbon double bond opens during addition polymerisation. Different polymerisation processes produce different polyethylene structures and grades.

Identifiers

Formula

C2H4

Functional group

C=C

Molar mass

28.05 g/mol

Also known as

ethylene, ethene

Properties

Melting Point

-169.18 °C

Boiling Point

-103.8 °C

Liquid density

0.56765 g/cm³ at −103.77 °C and 1.013 bar

Water solubility

In water, 131 mg/L at 25 °C

Related compounds

• Alkenes

  The alkene monomer used to make polyethylene, including LDPE.

Connected reactions

• Hydration: Ethene → Ethanol

  Ethene gives ethanol through hydration.

• Dehydration: Ethanol → Ethene

  Ethanol gives ethene through dehydration.

• Elimination: Bromoethane → Ethene

  The base removes a hydrogen from the carbon next to bromine. The C-H electrons form the C=C pi bond as bromide departs, so elimination removes H and Br without changing the two-carbon skeleton.

References

1. Poly(ethene): structure, manufacture and usesChemical Industry Education Centre, University of York
2. PubChem: EtheneNational Center for Biotechnology Information

   Identity retrieved 2026-09-08; matched against the record's isomeric structure. Unspecified stereochemistry remains unspecified.

3. Hazardous Substances Data Bank (HSDB): Ethene — melting pointHazardous Substances Data Bank (HSDB)

   Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/6325#section=Melting-Point. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 95th Edition. CRC Press LLC, Boca Raton: FL 2014-2015, p. 3-256

4. Hazardous Substances Data Bank (HSDB): Ethene — boiling pointHazardous Substances Data Bank (HSDB)

   Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/6325#section=Boiling-Point. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 95th Edition. CRC Press LLC, Boca Raton: FL 2014-2015, p. 3-256

5. Air Liquide Gas Encyclopedia: Ethylene — liquid densityAir Liquide

   Liquid ethene density: 567.65 kg/m³ at −103.77 °C and 1.013 bar, checked 2026-09-08. Conversion: 1 g/cm³ = 1000 kg/m³.

6. Hazardous Substances Data Bank (HSDB): Ethene — solubilityHazardous Substances Data Bank (HSDB)

   Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/6325#section=Solubility. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: McAuliffe C; J Phys Chem 70: 1267-75 (1966)