Fehling’s reagent is a chemical solution used to test for the presence of reducing sugars and other compounds with aldehyde functional groups. It is a mild oxidizing agent prepared by mixing two separate solutions: Fehling’s A (a solution of copper (II) sulfate) and Fehling’s B (a solution of potassium sodium tartrate and sodium hydroxide). When heated with a sample containing reducing sugars, it forms a red precipitate of copper(I) oxide, indicating a positive result.Principle: The copper(II) ions in the reagent are reduced to copper(I) ions by the reducing sugar. This reaction forms a brick-red precipitate of copper(I) oxide (𝐶𝑢2𝑂).Uses: It is used to test for the presence of reducing sugars, like glucose, and to differentiate between aldehydes and ketones.Result: A positive test is indicated by the formation of a red precipitate.