Reactions of Alkenes

• Alkenes are unsaturated.
• Alkenes have a carbon double bond.
• Alkenes have at least one carbon.
• The carbon double bond can bond to other atoms of another molecule.
• If hydrogen and a catalyst is added to an alkene, the double bond will break apart and the hydrogen atoms will be able to bond with the carbons. 
• When hydrogen and a catalyst is added, a saturated hydrocarbon, an alkane are produced.
• Water, a catalyst and high temperatures are introduced. 

  The double bond of the alkene opens.

  The water splits into a hydrogen atom and an O-H group.

  They bond to the carbon atoms.

  Because the new molecule has an O-H group it is now an alcohol.

  
• To separate water and ethanol, fractional distillation is used.
• Fractional distillation of ethanol and water:

  1. The mixture is heated.
  2. The ethanol boils first and evaporates up the column.
  3. It then condenses into a separate beaker.
  4. The water remains in the heating flask.
• Reactions between alkenes and halogens is the same as between hydrogen, but it doesn't require a catalyst.
• The most common example of a halogen and an alkene reacting is the bromine water test.
• Alkenes are able to react with bromine but alkanes are not.