Identify the correct order of acidity for: ${\text{C}}_6{\text{H}}_5\text{OH}$, ${\text{CH}}_3{\text{CH}}_2\text{OH}$, and ${\text{CH}}_3\text{COOH}$.

Solution

1. Compare the stability of the conjugate bases: ${\text{CH}}_3{\text{COO}}^{-}$, ${\text{C}}_6{\text{H}}_5{\text{O}}^{-}$, and ${\text{CH}}_3{\text{CH}}_2{\text{O}}^{-}$.
2. The ${\text{CH}}_3{\text{COO}}^{-}$ has two equivalent resonance structures, making it the most stable.
3. The ${\text{C}}_6{\text{H}}_5{\text{O}}^{-}$ is stabilized by resonance into the ring, but less effectively than the carboxylate.
4. The ${\text{CH}}_3{\text{CH}}_2{\text{O}}^{-}$ is destabilized by the electron-donating alkyl group.
5. Hence the answer is (A).