Question

Which of the following reactions of benzene proves the presence of three carbon-carbon double bonds in it?

• A. Formation of a triozonide with ozone
• B. Hydrogenation of benzene to cyclohexane
• C. Formation of $C_6{H}_{6}C{l}_6$ by addition of chlorine
• D. Formation of nitobenzene on heating benzene with a mixture of concentrated nitric acid and suphuric acid

Answer 1

Answer: (A), (B), (C)

The correct options are
A Formation of a triozonide with ozone
B Hydrogenation of benzene to cyclohexane
C Formation of $C_6{H}_{6}C{l}_6$ by addition of chlorine

Formation of a triozonide with ozone indicates that three double bonds are present. Each double bond forms an ozonide.
Hydrogenation of 1 mole of benzene to cyclohexane requires 3 moles of hydrogen. This also indicates the presence of 3 double bonds.
To one mole of benzene, 3 moles of chlorine are added to form 1,2,3,4,5,6-hexachlorocyclohexane $C_6{H}_{6}C{l}_6$. This also indicates the presence of 3 double bonds.