Question

The C - Cl bond length in chlorobenzene is shorter than that in $C{H}_3-Cl$ because

• A. Cl is attached to $s{p}^3$ hybridised C atom in $C{H}_3-Cl$ and attached to $s{p}^2$ hybridised C atom in chlorobenzene
• B. Cl is attached to $s{p}^2$ hybridised C atom in $C{H}_3-Cl$ and attached to $s{p}^2$ hybridised C atom in chlorobenzene
• C. Cl is attached to $s{p}^2$ hybridised C atom in $C{H}_3-Cl$ and attached to $s{p}^3$ hybridised C atom in chlorobenzene
• D. Cl is attached to $s{p}^3$ hybridised C atom in $C{H}_3-Cl$ and attached to $s{p}^3$ hybridised C atom in chlorobenzene

Answer 1

The correct option is A Cl is attached to $s{p}^3$ hybridised C atom in $C{H}_3-Cl$ and attached to $s{p}^2$ hybridised C atom in chlorobenzene

The $C-Cl$ bond length in chlorobenzene is shorter than in $C{H}_3-Cl$. As in chloromethane carbon holding chloride is $s{p}^3$ hybridised, while in chlorobenzene it is $s{p}^2$ hybridized. The delocalisation of electrons by resonance in chlorobenzene attribute for partial double bond character due to which bond length is shorter than a single bond. Hence the correct answer will be option (a).