In the copper reduction methods, what is the initial product formed when glucose reduces copper sulfate?

• A. Cuprous oxide
• B. Copper metal
• C. Cupric oxide
• D. Copper sulfate remains

Answer: (A)

Reducing sugars like glucose donate electrons to copper(II) in copper sulfate under the alkaline, heated conditions used in Benedict’s-type tests. The first reduction step converts Cu2+ to Cu+, which appears as copper(I) oxide, Cu2O, as a brick-red precipitate. This is the initial product you’d observe; copper metal isn’t formed in this procedure, and copper(II) oxide would require a different redox pathway. So the initial product formed is cuprous oxide, Cu2O.