General Organic Chemistry (GOC) - 2 - Free MCQ Test with solutions

II = III > I = IV
In II and III, there is resonance energy from two aromatic rings, so they are more stable, whereas in I and IV, there is resonance energy from only one aromatic ring.

(i, ii, v, vi, ix)

C₁–C₂ is shorter because it is double bond in two of three resonance strucutre ; C₂–C₃ is a single bond in two of three resonance strucutres.

Lack of vacant orbital

Stability ∝ Number of hyperconjugative H-atoms.

(i, iii, iv, v, vii)

The user-reported error is valid because the provided answer and the solution are inconsistent. The answer given is option B (3), but the solution lists five pairs (i, iii, iv, v, vii) that do not represent resonating structures, which corresponds to 5, not 3. This discrepancy indicates a factual error in either the final answer or the solution explanation. Based on the solution's detailed analysis of each pair, the correct count of sets that do not represent resonating structures should be 5. Therefore, the answer should be option A (5), aligning with the solution's identification.

C₂ and C₄

IV > III > II > I

Boron is sp² hybridized having vacant p–orbital.