NTA Abhyas JEE Main2020ChemistryChemical Bonding and Molecular StructurePractice
Which of the following statements are correct for butadiene C 4 H 2 = C 3 H - C 2 H = C 1 H 2 (1) The C 1 - C 2 and C 3 - C 4 bonds are longer than a carbon-carbon double bond. (2) The C 1 - C 2 and C 3 - C 4 bonds are shorter than a carbon-carbon double bond. (3) The C 2 - C 3 bond is slightly shorter than a carbon-carbon single bond. (4) The C 2 - C 3 bond is slightly longer than a carbon-carbon double bond.
Options
- A1, 2
- B2, 3
- C1, 3
- D3, 4
Correct answer
C. 1, 3
Step-by-step solution
Consider the following resonance structure The structures (2) and (3) show the partial single-bond character of the C 1 - C 2 and C 3 - C 4 bonds, and (4) and (5) the partial double-bond character of the C 2 - C 3 bond. This explains the observed anomalies in the bond distances.