Question
Question: Identify the compound with highest acidic strength from following....
Identify the compound with highest acidic strength from following.
A
Ethanol
B
t-Butyl alcohol
C
Phenol
D
p-Nitrophenol
Answer
p-Nitrophenol
Explanation
Solution
The acidic strength increases as pKa decreases. Approximate pKa values:
- Ethanol ≈ 16
- t‐Butyl alcohol ≈ 19
- Phenol ≈ 10
- p‐Nitrophenol ≈ 7 (due to the strong electron-withdrawing −NO₂ group)
Thus, p‑Nitrophenol is the most acidic.