Question

Why does glucose react with Cu^2+ even though Cu^2+ reacts only with aldehydes?

a) Glucose is an aldehyde
b) Glucose is a ketone
c) Cu^2+ reacts with both aldehydes and ketones
d) Glucose undergoes redox reactions with Cu^2+

Answer 1

Glucose reacts with Cu^2+ because it is an aldehyde with a reducing capability due to its aldehyde functional group.

Step-by-step explanation:

Glucose reacts with Cu2+ because glucose is an aldehyde. This reaction is characteristic of reducing sugars that contain an aldehyde group which can reduce metal ions such as copper. Glucose is a polyhydroxy aldehyde, with multiple -OH groups and an aldehyde functional group, allowing it to undergo redox reactions with metal ions like copper. Therefore, the correct answer to why glucose reacts with Cu2+ even though Cu2+ reacts only with aldehydes is that glucose is an aldehyde. This is illustrated by the fact that glucose can be oxidized to D-gluconic acid in the presence of oxidizing agents, indicating the presence of an aldehyde group.