MHT CET202525 Apr 2025Evening ShiftChemistryAlcohols Phenols and EthersActual
Which of the following reagents is used in the conversion of phenol into picric acid?
Options
- Adil. HNO ₃
- Bdil. HNO ₂
- Cconc. HNO ₃+ conc. H ₂ SO ₄
- Dconc. H ₂ SO ₄
Correct answer
C. conc. HNO ₃+ conc. H ₂ SO ₄
Step-by-step solution
Phenol undergoes electrophilic aromatic substitution with concentrated nitrating mixture to produce picric acid (2,4,6-trinitrophenol). Due to phenol's high reactivity, dilute nitric acid causes oxidation side products, while nitrous acid serves diazotization purposes. The mixture of concentrated nitric and sulfuric acids generates the nitronium ion electrophile ( NO₂^+ ) required for efficient trinitration. Sulfuric acid both activates the electrophile and protects against oxidative degradation through initial sul