Question

Glucose gives positive silver mirror test with ammoniacal silver nitrate because it contains :

• A. hydroxyl group
• B. aldehyde group
• C. ketone group
• D. vicinal diol group

Answer 1

The correct option is B aldehyde group

The Tollen's test is used in organic chemistry to test for the presence of aldehydes. In this reaction, an aldehyde is oxidized to a carboxylic acid while the $A{g}^{1+}$ is reduced to sliver metal, which deposits as a thin film on the inner surface of the glass. The generic reaction is as follows and is specific for aldehydes:

Tollens Test (Silver Mirror): An aldehyde is oxidized by silver (I) to generate a carboxylic acid and silver metal.
As glucose gives this test so it has aldehyde group