Q22. How do you explain the presence of an aldehydic group in a glucose molecule?
Answer: Glucose reacts with hydroxylamine to form a monoxime. It adds one molecule of hydrogen cyanide to give cyanohydrin, so it contains a carbonyl group which can be an aldehyde or a ketone. On mild oxidation with bromine water, glucose gives gluconic acid, a six-carbon acid. This indicates that the carbonyl group present in glucose is an aldehydic group.
