The correct increasing order of textC-H (A)$\text{C-H (A)}$, textC-O (B)$\text{C-O (B)}$, textC=O (C)$\text{C=O (C)}$ and textCequivtextN (D)$\text{C}\equiv\text{N (D)}$ bonds in terms of covalent bond length is: (1) A < B < C < D$A < B < C < D$ (2) A < D < C < B$A < D < C < B$ (3) D < C < B < A$D < C < B < A$ (4) D < C < A < B$D < C < A < B$

### Core Logic Comparing bond lengths: - C–H (A): sim 107 text pm$\sim 107 \text{ pm}$ - C≡N (D): sim 116 text pm$\sim 116 \text{ pm}$ - C=O (C): sim 121 text pm$\sim 121 \text{ pm}$ - C–O (B): sim 143 text pm$\sim 143 \text{ pm}$ ### Step 1: Final Conclusion Thus, the increasing order is A < D < C < B$A < D < C < B$, corresponding to option (2). ### Pattern Recognition Sees: covalent bond length comparison across bond orders and atomic radii. Trap: Assuming triple bonds are always longer or shorter without accounting for smaller atomic radii like hydrogen. ### Chapter Mix Class 11 Chemistry: Chemical Bonding and Molecular Structure