See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# Bond Strength Comparison - Option A **Understanding Bond Strength:** Bond strength depends on: 1. **Electronegativity of bonded atom** — higher electronegativity = stronger bond 2. **Bond order** — multiple bonds > single bonds 3. **Atomic size** — smaller atoms form stronger bonds --- **Analyzing Option (A):** Compare: $CH_3-CH_2-Br$ vs $CH_3-CH_2-Cl$ Both are $C-X$ single bonds (same bond order). **Electronegativity:** $Cl (3.0) > Br (2.8)$ **Atomic Size:** $Cl$ is smaller than $Br$ Both factors favor stronger bonding in **$C-Cl$ bond**. $$\text{Bond strength: } C-Cl > C-Br$$ The $C-Cl$ bond is **stronger** ✓ --- **Why other options fail:** - **(B)** $C=C-Br$ vs $C-CH(Br)-CH_3$: Secondary $C-Br$ (more stable) is NOT stronger than conjugated $C=C$ bond - **(C)** Aromatic $C-Cl$ vs aliphatic $C-Cl$: Aromatic is stronger, but question asks which is indicated as stronger (ambiguous) - **(D)** $C=C$ conjugated vs $C=C$ aliphatic: Both are similar $C=C$ bonds - **(E)** $C=C$ vs $C-NO_2$: $C=C$ is stronger but $NO_2$ makes the single bond stronger - **(F)** Identical aromatic $C-C$ bonds (no difference) **Answer: (A)** — The $C-Cl$ bond is unambiguously stronger due to chlorine's higher electronegativity and smaller size.