Q4 / 160 · WBJEE 2011 · Chemistry
The correct order of decreasing acidity of nitrophenols will be
- Am-Nitrophenol \( > \) p-Nitrophenol \( > \) o-Nitrophenol
- Bo-Nitrophenol \( > \) m- Nitrophenol \( > \) p-Nitrophenol
- Cp-Nitrophenol \( > \) m- Nitrophenol \( > \) o-Nitrophenol
- Correct answerDp-Nitrophenol \( > \) o-nitrophenol \( > \) m-Nitrophenol
Solution
Hints: 
Due to \(-\mathrm{I}\) and \(-\mathrm{R}\) influence, \(\mathrm{NO}_2\) in ortho-postion should have raised the acidity to the maximum extent. But it is due to intramolecular \(\mathrm{H}\) - bonding, ortho-nitrophenol is less acidic than para - nitrophenol.
Due to \(-\mathrm{I}\) and \(-\mathrm{R}\) influence, \(\mathrm{NO}_2\) in ortho-postion should have raised the acidity to the maximum extent. But it is due to intramolecular \(\mathrm{H}\) - bonding, ortho-nitrophenol is less acidic than para - nitrophenol.
Hence, the correct answer is option: 'D'.