See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# C–O Bond Length Comparison **Step 1: Determine the structure and bonding of each species** - **$CO$**: Linear, triple bond ($C \equiv O$), bond order = 3 - **$CO_2$**: Linear, two double bonds ($O=C=O$), each C–O bond order = 2 - **$CO_3^{2-}$**: Trigonal planar, three resonance structures with one single and two double bonds, average bond order ≈ 1.33 **Step 2: Apply bond order–bond length relationship** Higher bond order → shorter bond length (stronger bond, electrons more tightly held) $$\text{Bond Order: } CO (3) > CO_2 (2) > CO_3^{2-} (1.33)$$ **Step 3: Rank by increasing bond length** Since bond length is inversely proportional to bond order: $$CO < CO_2 < CO_3^{2-}$$ **Why (D) is correct:** The triple bond in $CO$ is shortest, the double bonds in $CO_2$ are intermediate, and the resonance-stabilized single/double bonds in $CO_3^{2-}$ are longest due to lowest average bond order. **Answer: (D) $CO < CO_2 < CO_3^{2-}$**