10-20. organic chemistry

• Kekulé's proposed structure for benzene:

  1. all C-C/C=C bonds would be different lengths and strengths
  2. enthalpy of hydrogenation would be -320 kJ/mol
  3. benzene would undergo addition reactions
  4. two possible isomers for 1,2-disubstituted benzene compounds
• Actual structure of benzene:

  1. all C to C bonds are of equal strength
  2. enthalpy of hydrogenation is -210 kJ/mol
  3. benzene undergoes substitution reactions
  4. only one isomer exists for 1,2-disubstituted benzene compounds
• Structure of benzene:

  1. planar regular hexagon
  2. bond angle 120°
  3. benzene ring (delocalised electrons within the benzene molecule)