alkanes and alkenes

• Alkanes


  A subset of hydrocarbons whose names all end in -ane
• First eight alkanes


  • Methane
  • Ethane
  • Propane
  • Butane
  • Pentane
  • Hexane
  • Heptane
  • Octane
• Mnemonic


  Can make learning the names of the first eight alkanes easier
• Alkanes


  • Contain more than double the number of hydrogen atoms than carbon atoms
  • General formula: C_n H_{2n+2}
• Alkenes

  • A subset of hydrocarbons whose names all end in -ene
  • Contain a carbon to carbon double bond which makes them more reactive than alkanes
  • Contain twice as many hydrogen atoms as carbon atoms
  • General formula: C_n H_{2n}
• Alkenes


  Are more reactive than alkanes because they have a double bond
• Bromine water test


  • Alkane remains orange-brown
  • Alkene turns colourless