See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# Acidity of Hydrogen Atoms – Step-by-Step Solution **Key Principle:** Hydrogen acidity increases when attached to nitrogen that is bonded to electron-withdrawing groups (EWGs). The more electron density withdrawn from nitrogen, the more polar and acidic the N–H bond. **Analysis of each option:** **(A) Amide (N–H):** Nitrogen bonded to one carbonyl carbon. Moderate electron withdrawal. **(B) Imide (N–H):** Nitrogen bonded to **two** carbonyl carbons. Strong electron withdrawal from both sides increases polarity of N–H significantly. **(C) Sulfonamide (N–H):** Nitrogen bonded to sulfone group ($SO_2$). The $SO_2$ group is highly electron-withdrawing due to: - Two oxygen atoms pulling electron density - Sulfur's electronegativity effect - Creates maximum polarization of the N–H bond **(D) Amine ($NH_2$):** No electron-withdrawing groups attached; N–H is least acidic. **Comparison:** Between (B) and (C), the sulfonamide's $SO_2$ group is more electron-withdrawing than even two carbonyls because of the combined effect of two oxygens and sulfur's higher oxidation state, making the hydrogen extremely acidic. **Answer: (C)** — The sulfonamide N–H contains the most acidic hydrogen due to maximum electron withdrawal by the $SO_2$ group.