Question

The correct increasing order of average bond length for C=C, N=O, C-C, N-O is

• A. C=C < N=O < C-C < N-O
• B. N-O < N=O < C-C < C=C
• C. C=C < C-C < N=O < N-O
• D. C-C < N=O < C=C < N-O
• E. N=O < C=C < N-O < C-C

Hint:

Chemistry Tip: Higher bond order means stronger bond and shorter bond length.

Answer 1

Answer: (E)

Concept:
Bond length depends mainly on: 1. Bond order (double bond shorter than single bond) 2. Atomic size (smaller atoms form shorter bonds)
Step 1: Compare single and double bonds.
Double bonds are shorter than corresponding single bonds: $$\text{N=O}<\text{N-O}$$ $$\text{C=C}<\text{C-C}$$
Step 2: Compare N=O and C=C.
Nitrogen and oxygen are smaller atoms than carbon, so N=O bond is shorter than C=C bond. Thus: $$\text{N=O}<\text{C=C}$$
Step 3: Compare N-O and C-C.
Though both are single bonds, N-O involves smaller atoms than carbon-carbon, so N-O is shorter than C-C. Thus: $$\text{N-O}<\text{C-C}$$
Step 4: Combine all orders.
Increasing bond length: $$\text{N=O}<\text{C=C}<\text{N-O}<\text{C-C}$$ Hence correct option is (E). :contentReference[oaicite:0]{index=0}