The correct increasing order of $\mathrm{C}-\mathrm{H}(\mathrm{A})$, $\mathrm{C}-\mathrm{O}(\mathrm{B})$, $\mathrm{C}=\mathrm{O}(\mathrm{C})$ and $\mathrm{C} \equiv \mathrm{N}(\mathrm{D})$ bonds in terms of covalent bond length is:

JEE Main · 2026 · 21 Jan 2026 · Shift 2 · Chemical Bonding and Molecular Structure

The correct increasing order of

C - H (A)

C - O (B)

C = O (C)

and

C \equiv N (D)

bonds in terms of covalent bond length is:

Answer: (B)

Bond length grows as bond order falls and as the bonded atoms become larger. The C-H bond is the shortest at about 107 pm. The triple

C \equiv N

bond, despite joining heavier atoms, is held short by its high bond order at about 116 pm. The double

C = O

bond is longer at about 121 pm, and the single

C - O

bond is the longest at about 143 pm. The increasing order of bond length is

C - H < C \equiv N < C = O < C - O

JEE Main · 2026 · 21 Jan 2026 · Shift 2 · Single correct option