benzene

Question 1

3 conclusions of the kekule structure

Answer 1

1) X-ray diffraction shows all bonds are equal

2) The energy for hydrogenation of benzene is lower than expected by -152kjmol

3) Benzene doesn’t undergo electrophilic addition, indicating it doesn’t have regular C=C bonds

Question 2

Benzene structure

Answer 2

• delocalised pi electrons around 6 carbons
• decreased electron density in the ring
• stable
• doesn’t undergo addition

Question 3

benzene to nitrobenzene

Answer 3

• conc HNO3 & conc H2SO4 with fuming HCl
• Reflux, 50 degrees

Question 4

benzene to 1-chlorobenzene

Answer 4

• Cl2 & FeCl3
• Reflux

Question 5

benzene to 1-ethylbenzene (alkylation)

Answer 5

• haloalkane
• anhydrous AlCl3 (dry ether)
• room temp

Question 6

benzene to 1-ethanoylbenzene (acylation)

Answer 6

• acyl chloride
  -anhydrous AlCl3 (dry ether)
• reflux 50 degrees