Question:
The compound with the lowest pKa value is
The compound with the lowest pKa value is
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Acidity: p-nitrophenol $>$ phenol $>$ alcohols.
Updated On: Apr 27, 2026
- ethanol
- phenol
- p-nitrophenol
- o-cresol
- p-cresol
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Verified By Collegedunia
The Correct Option is C
Solution and Explanation
Step 1: Concept
Lower $pK_a$ value indicates higher acidity.
Step 2: Meaning
Electron-withdrawing groups (like $-NO_2$) increase the acidity of phenols.
Step 3: Analysis
The nitro group at the para position stabilizes the phenoxide ion through resonance and inductive effects.
Step 4: Conclusion
Hence, the correct answer is p-nitrophenol.
Final Answer: (C)
Lower $pK_a$ value indicates higher acidity.
Step 2: Meaning
Electron-withdrawing groups (like $-NO_2$) increase the acidity of phenols.
Step 3: Analysis
The nitro group at the para position stabilizes the phenoxide ion through resonance and inductive effects.
Step 4: Conclusion
Hence, the correct answer is p-nitrophenol.
Final Answer: (C)
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