HALOGENS REACTION WITH ALKENES

• HALOGENS REACTION WITH ALKENES:

  • RAPID reaction
  • No CATALYST needed
• CHLORINE REACTION:

  • Carbon to carbon DOUBLE bond- becomes a carbon to carbon SINGLE bond (bond BROKEN)
  • CHLORINE molecule- feed across SINGLE bond

  
• GENERAL EQUATION: CHLORINE

  ALKENE + CHLORINE -> DICHLORO(ALKANE)
• BROMINE AND IODINE REACT IN THE SAME WAY:

  ALKENE + BROMINE -> DIBROMO(ALKANE)

  ALKENE + IODINE -> DIIODO(ALKANE)

  
• HOW CAN THE REACTION WITH BROMINE BE USED TO DISTINGUISH BETWEEN ALKENES AND ALKANES?

  • Alkenes- DOUBLE bond- more REACTIVE than ALKANES (when added to BROMINE- colour change from ORANGE to COLOURLESS)
  • Alkanes- SATURATED (no DOUBLE bonds) - have no REACTION with BROMINE