Question

Which does not give silver mirror with ammoniacal $AgN{O}_3$?

• A. Aliphatic ketone
• B. Acetaldehyde
• C. $\alpha$-hydroxy ketone​ (terminal)
• D. Formic acid

Answer 1

The correct option is A Aliphatic ketone

Aliphatic ketone does not give silver mirror test because it doesn't have -CHO group. Formic acid gives Tollens' and Fehling's tests while other carboxylic acids ​do not due to the presence of an aldehydic C-H bond that can be oxidized further in the presence of mild oxidizing agents like Tollens' and Fehling's reagents. $\alpha$-hydroxy ketone​ (terminal) gives Tollens' and Fehling's test because they can be converted into 𝛼-hydroxy aldehyde under basic conditions.​ Hence, the correct answer is option (a).