alkenes

• • alkenes are unsaturated because they have a double carbon bond
  • they contain two fewer hydrogen atoms than alkane with same number of carbon atoms
• • alkenes are more reactive than alkanes
  • this is because double carbon bond can open to make single bond
  • so, can bond two more carbon atoms
• • the formula for alkenes is C(n)H(2n)
• • the first four alkenes are:
  • ethene
  • propene
  • butene
  • pentene
• • when alkenes brurn, they burn incompletely
  • alkene + oxygen -> carbon + carbon monoxide + carbon dioxide + water
  • incomplete combustion produces a smoky yellow flame and less energy than complete combustion