KCET2017Chemistryp Block Elements (Group 15, 16, 17 & 18)
Which of the following order is true regardingthe acidic nature of phenol?
Options
- APhenol > O-cresol > o-nitrophenol
- BO-cresol < phenol < O-nitrophenol
- Cphenol O-nitrophenol
- Dphenol < O-cresol < O-nitrophenol
Correct answer
B. O-cresol < phenol < O-nitrophenol
Step-by-step solution
Acidity of the substituted phenols is affected by the nature of the substituents. Presence of ( e⁻ )withdrawing group such as ( - NO ₂ ) increases the acidic strength whereas ( e⁻ )releasing or donating groups at 0- and p- position decreases acidic strength of substituted phenol. In cresol (o- or p- cresol) methyl groups shows + I effect, soit destabilizes the anion formed after ionization hence cresol is less acidic and o-nitrophenol is more acidic than carbolic acid (phenol). Hence, the correct order for the acid