mechanism - substitution reaction

• What are the three main steps in an addition reaction called?

  Initiation, propagation, and termination.
• What does an addition reaction with alkanes make?

  a haloalkane
• What happens in the initiation step?

  Homolysis, or homolytic action.
• What is homolysis/homolytic action?

  When a bond is split to make two products that are the same.
• What is created by the initiation step in the creation of halo alkanes?

  Two Cl or Br radicals.
• What is a radical?

  An atom that has at least one unpaired valence electron.
• What are the conditions needed for this initiation step?

  UV light is needed

  Room temperature

  The reaction must occur in the light.
• Sum up the initiation step of the production of haloalkanes.

  • a chlorine or bromine molecule undergoes homolysis/homolytic action, creating two very reactive bromine/chlorine radicals.
  • This is a very endothermic reaction
  • For this to occur, the reaction mustn't be in the dark, there must be UV light and room temperature at least must be achieved.