See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

## Solution: Identifying the Strongest Acid **Step 1: Recognize the compounds** All options are substituted phenols (aromatic $OH$ groups). Acid strength depends on how easily the phenolic proton dissociates, determined by stability of the resulting phenoxide anion. **Step 2: Apply inductive effect principle** The stability of the phenoxide anion increases when electron-withdrawing groups are attached to the benzene ring. Electron-withdrawing groups stabilize the negative charge on oxygen through resonance and inductive effects. **Step 3: Compare substituents by electronegativity** - **(A) Chlorine ($Cl$):** Highly electronegative; strong electron-withdrawing group - **(B) Bromine ($Br$):** Less electronegative than $Cl$; weaker electron-withdrawing effect - **(C) Hydrogen:** No electronic effect (reference compound, phenol) - **(D) Methyl ($CH_3$):** Electron-donating group; weakens acidity **Step 4: Order by acid strength** $$\text{Cl (EWG)} > \text{Br (EWG)} > \text{H} > \text{CH}_3 \text{(EDG)}$$ **Conclusion:** Chlorine's high electronegativity maximally stabilizes the phenoxide anion, making **3-chlorophenol (A)** the strongest acid among these options. **Answer: (A)**