See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# Bond Length Order Analysis **Key Principle:** Bond length decreases with increasing bond order: Single < Double < Triple Also: For the same bond type, shorter bonds occur in more electronegative environments. --- ## **Option (A): $C-C > C=C > C \equiv C > C \equiv N$** - $C-C$: single bond (~154 pm) - $C=C$: double bond (~134 pm) - $C \equiv C$: triple bond (~120 pm) - $C \equiv N$: triple bond with N (more electronegative) (~116 pm) **✓ Correct.** Triple bond with N is shortest due to higher electronegativity pulling electron density, strengthening the bond. --- ## **Option (C): $C=C > C=N > C=O$** - $C=C$: double bond (~134 pm) - $C=N$: double bond with N (~129 pm) - $C=O$: double bond with O (~122 pm) **✓ Correct.** As electronegativity increases ($C < N < O$), the double bond becomes stronger and shorter due to increased electron withdrawal. --- ## **Why others fail:** - **(B)** Claims $C=N > C=O$, but O is more electronegative than N, making $C=O$ shorter. ✗ - **(D)** Claims $C=C > C \equiv C$, but triple bonds are shorter than double bonds. ✗ - **(E)** Claims $C-H > C-C$, but C-H is shorter (~109 pm vs 154 pm). ✗