Chemistry · Phenols: Acidic nature, electrophilic substitution reactions, halogenation, nitration and sulphonation, Reimer Tiemann reaction
Which of the following is true regarding acidity of phenol?
Which of the following is true regarding acidity of phenol?
- A. It is a stronger acid than carbonic acid
- B. It is a stronger acid than benzoic acid.
- C. It is a stronger acid than water
- D. It is a stronger acid than benzene sulphonic acid
Step-by-step solution
Phenol has a pKa of approximately 10, while water has a pKa of 15.7. Since a lower pKa indicates a stronger acid, phenol is a stronger acid than water. Carbonic acid (pKa1 ≈ 6.4), benzoic acid (pKa ≈ 4.2), and benzene sulfonic acid (very strong acid, pKa < 0) are all stronger acids than phenol, so only option C is correct.