Phenol can be distinguished from alcohol by which reagent:

• (a) Na
• (b) Alcoholic FeCl₃
• (c) Br₂/HOH
• (d) NaOH

Phenol can be distinguished from alcohol using the reagent alcoholic FeCl₃ (option b). This reagent reacts with phenol to form a colored complex, while alcohol does not produce a similar reaction.

Why Alcoholic FeCl₃ Works

When phenol is mixed with alcoholic FeCl₃, it forms a violet or purple complex due to the formation of phenoxide ions. This color change is a clear indicator of the presence of phenol.

Other Reagents Explained

• Na (Sodium): This can react with alcohols but does not specifically distinguish phenol.
• Br₂/HOH: This reagent can react with both phenols and alcohols, making it unsuitable for differentiation.
• NaOH: This base can react with both compounds but does not provide a distinct identification.

In summary, the best choice for distinguishing phenol from alcohol is alcoholic FeCl₃ due to its ability to produce a noticeable color change.