Monosaccharides such as glucose, fructose and galactose can donate electrons to other compounds.Molecules that can donate electrons are called reducing agents.Benedict's reagent is an alkaline solution of copper(II) sulfate. Copper(II) sulfate can be reduced to insoluble copper(I) oxide which has an orange-red colour.2cm3 of the sample to be tested is added to a test tube. 2cm3 of Benedicts is added and the mixture is boiled in a water bath for 5 minutes.If reducing sugar is present an orange-red precipitate is formed.