Question

Justify that glucose is an aldose form of sugar, with the help of a chemical reaction.

Answer 1

When glucose reacts with a mild oxidizing agent like bromine water (Br₂/H₂O), the aldehyde group (−CHO) at the first carbon is oxidized to a carboxylic acid (−COOH) group, forming gluconic acid, while the rest of the chain remains unaffected.

\[\ce{\underset{Glucose (Aldose)}{CHO(CHOH)4CH2OH} ->[Br2/H2O][]\underset{Gluconic Acid}{COOH(CHOH)4CH2OH}}\]