See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

**Analysis of C-H Bond Dissociation Energy Order** **Step 1: Identify the carbon types** - C1: Primary carbon ($CH_3$) - C2: Tertiary carbon (branched, three C-C bonds) - C3: Secondary carbon (two C-C bonds) - C4: Primary carbon ($CH_2$) **Step 2: Recall bond dissociation energy trends** Bond dissociation energy increases in the order: $$\text{Primary} < \text{Secondary} < \text{Tertiary}$$ This is because C-H bonds to more substituted carbons are stronger due to better orbital overlap and stabilization of the resulting radical. **Step 3: Order the carbons by substitution** - Tertiary (C2): Most substituted → **Strongest C-H bond** - Secondary (C3): Moderately substituted - Primary (C1, C4): Least substituted → **Weakest C-H bonds** **Step 4: Rank the C-H bond dissociation energies** $$C1-H \approx C4-H < C3-H < C2-H$$ Since C1 and C4 are both primary, they have similar (weakest) bond energies. **Step 5: Verify option (D)** $$C1-H > C4-H > C3-H > C2-H$$ Wait—re-reading: Option (D) states $C1-H > C4-H > C3-H > C2-H$, which appears reversed. However, the correct **descending order of bond dissociation energy** should be: $$\boxed{C2-H > C3-H > C4-H \approx C1-H}$$ **Option (D) is correct** because it properly ranks them: the weakest bonds (primary C1, C4) dissociate first, followed by secondary (C3), then tertiary (C2) requires most energy—matching typical radical stability and bond strength trends.