See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# Acidity Order Analysis **Step 1: Identify the effect of substituents on $COOH$ acidity** Acidity of benzoic acids depends on whether substituents are **electron-withdrawing (EWG)** or **electron-donating (EDG)**: - **EWG** stabilizes the carboxylate anion ($COO^-$) → increases acidity - **EDG** destabilizes the anion → decreases acidity **Step 2: Classify each substituent** | Compound | Substituent | Type | Effect | |----------|------------|------|--------| | (I) | $-CH_3$ | EDG | Decreases acidity | | (II) | $-Cl$ | EWG | Increases acidity | | (III) | $-NO_2$ | Strong EWG | Greatly increases acidity | | (IV) | $-OCH_3$ | EDG | Decreases acidity | **Step 3: Order by acidity (strongest → weakest)** $$\text{(III)} > \text{(II)} > \text{(I)} > \text{(IV)}$$ - **(III)** most acidic: $NO_2$ is the strongest EWG (withdraws electrons via resonance and induction) - **(II)**: $Cl$ is weakly EWG - **(I)**: $CH_3$ is weakly EDG - **(IV)** least acidic: $OCH_3$ is strongly EDG (donates via resonance) **Answer: (D) $\mathbf{(III) > (II) > (I) > (IV)}$** ✓