It is a chemical test that is used to check the presence of reducing sugars.
The functional group in simple carbohydrates are free ketone or aldehyde which can be identified by this test.
This test is based on Benedict’s solution or reagent (which is a complex mixture of sodium citrate, sodium carbonate, and the pentahydrate of copper(II) sulfate), which is an alkaline solution that contains copper sulphate, sodium citrate and sodium carbonate.
Benedict’s test principle:
When reducing sugars are exposed to Benedict’s solution, then it results in the formation of brick-red precipitate that indicates a positive test.
The chemical reaction is shown below in the image.