Question

Rank the following species in order of decreasing nucleophilicity in a polar protic solvent:

• A. $3>1>2$
• B. $2>3>1$
• C. $1>3>2$
• D. $2>1>3$

Answer 1

The correct option is D $2>1>3$

In polar protic solvent, less hydrogen bonding nucleophile is more nucleophilic. So, $2$ is more nucleophilic than others. Comparing $1$ and $3$, $1$ is more nucleophilic than $3$ because in (3) negative charge is delocalized on two $O$ atoms due to resonance and less available for donation.
Hence, (d) is correct.