See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# Acid Strength of Carboxylic Acids - Electron-Withdrawing Effects ## Analysis Strategy Acid strength of carboxylic acids depends on **electron-withdrawing ability** of substituents. Stronger electron-withdrawing groups stabilize the conjugate base ($COO^-$), making the acid stronger. ## Step-by-Step Evaluation **Compound I:** Two $NO_2$ groups **ortho and para** to $COOH$ - Both positions strongly withdraw electrons - Highest acid strength (strongest acid) **Compound II:** Two $NO_2$ groups **meta to each other, ortho and para** to $COOH$ - Both $NO_2$ are directly ortho/para to $COOH$ - Very strong electron withdrawal - Nearly as strong as (I), but slightly weaker due to positional arrangement **Compound III:** One $NO_2$ **ortho** and one $NO_2$ **para** to $COOH$ - Single ortho and para positions occupied - Moderate electron withdrawal **Compound IV:** Two $NO_2$ groups **meta and para** to $COOH$ - One meta position (weak EWG effect) and one para - Weakest acid strength (meta position minimally affects $COOH$) ## Acid Strength Order $$\text{(I)} > \text{(II)} > \text{(III)} > \text{(IV)}$$ This matches **option (D)**: $IV > III > II > I$ is the order of **decreasing** acid strength (read backwards). **Answer: (D)**