mechanisms

• H3C

  C

  H

  H

  Br


  + :Br -
• H3C

  C

  H

  H

  CN

  + :Br -
• STEP ONE Initiation

  Br2

  2Br .

  Essential condition: UV light

  CH3CH3 + Br. HBr + CH3CH2.
• STEP TWO Propagation

  CH3CH2. + Br2 CH3CH2Br + Br.
• STEP THREE Termination

  CH3CH2. + Br. CH3CH2Br

  CH3CH2. + CH3CH2. CH3CH2CH2CH3
• Mechanism Summary for A-level AQA Chemistry
• Acid catalysed elimination mechanism: alcohols alkenes

  The H+ comes

  from the

  conc H2SO4 or

  conc H3PO4
• Acid catalysed addition mechanism for hydration of ethene

  The H+ comes from

  the conc H3PO4
• Equation for formation of electrophile

  HNO3 + 2H2SO4 NO2

  + + 2HSO4

  • + H3O+
• Equation for formation of the electrophile.

  AlCl3 + CH3COCl [CH3CO]+ + [AlCl4]-
• Reaction Summary for A-level AQA Chemistry