Question

Which of the following compound will show a positive silver mirror test?

Options

• HCOOH

• CH₃(CHOH)₃CHO

• CH₃CO(CHOH)CH₃

• Both HCOOH and CH₃(CHOH)₃CHO

Answer 1

Both HCOOH and CH₃(CHOH)₃CHO

Explanation:
Compounds with Tollen's reagent are reduced to silver mirror by the –CHO group. It's known as the silver mirror test.

\[\begin{array}{cc}
\ce{O}\phantom{..}\\
||\phantom{..}\\
\ce{\underset{(a)}{H - C - OH}}
\end{array}\]

\[\begin{array}{cc}
\phantom{...............}\ce{O}\\
\phantom{...............}||\\
\ce{\underset{(b)}{CH3 - (CHOH)3 - C - H}}
\end{array}\]

Both (a) and (b) have \[\begin{array}{cc}
\ce{O}\phantom{..}\\||\phantom{..}\\\ce{- C - H}
\end{array}\] group, so both of them give a positive silver mirror test.