Cracking

• Cracking is done because there is a high demand for short chain hydrocarbons (for fuels)
• In cracking, a long chain hydrocarbon is broken down to produce a more useful shorter chain hydrocarbon, and also produces an alkene
• Conditions for catalytic cracking

  . High temperatures

  . Catalyst
• Conditions for steam cracking

  . High temperatures

  . Steam
• Allende’s have a double covalent bond between two carbon atoms
• Why are alkenes useful

  . Make polymers

  . Starting material to make other chemicals
• alkenes are more reactive than alkanes
• How to test for alkenes

  . Bromine water (orange)

  . Shake the alkene with the bromine water

  . If alkene is present, bromine water will turn colourless