enedict's reagent is made by complexing Cu+2 (from Copper sulfate) ions with citric acid in a basic medium(Sodium Carbonate. Benedict's Reagent is used to detect reducing sugars. What the reagent does is to oxidize aldehydes or alpha hydroxyl ketones. When this happens the color of the reagent turns from blue to colorless by the reduction of copper(II) to Copper(I) that is colorless.