Question

What type of reaction occurs when glucose reacts with the Benedict's solution. Explain what chemical change glucose and reagent in Benedict's solution undergoes. Give the names of products.

Answer 1

Benedicts reagent is a complex mixture of sodium carbonate, sodium citrate, and copper(II) sulphate pentahydrate. When glucose is mixed with benedicts reagent and heated, a reduction reaction occurs in which the benedicts reagent changes color. The color varies from green to dark red or brick colour or rusty brown colour which depends on the type and amount of sugar present in it. Glucose never produces violet colour precipitate with benedicts solution. Its used to test simple sugars like glucose and produces a clear blue solution of sodium and copper salts and in the presence of sugar blue color changes to green, yellow and brick red colour. Color changes because it donates its electrons. The cupric ions present in benedicts solution reacts with aldehyde group to form carboxylic acid and cuprous oxide( brick red precipitate).