Which phenol derivative has the highest acidity among the following?
2,4,6-Trinitrophenol (picric acid) is the most acidic due to three electron-withdrawing -NO₂ groups stabilizing the phenoxide ion via resonance and inductive effects.
Ref: NCERT Class 12 Chemistry > Chapter 7: Alcohols, Phenols and Ethers > Topic: Physical Properties and Acidity of Alcohols and Phenols