Which of the following reagents is used to distinguish between a reducing sugar and a non-reducing sugar?

Solution

1. Reducing sugars contain a free or potentially free aldehyde or ketone group.
2. These groups can reduce metal ions in alkaline solutions.
3. Benedict's reagent contains ${\text{Cu}}^{2+}$ ions which are reduced to ${\text{Cu}}^{+}$ forming a red precipitate.
4. Hence the answer is (A).