Benedict's reagent is a chemical solution used to test for the presence of reducing sugars, such as glucose and fructose. It contains copper(II) sulfate, sodium carbonate, and sodium citrate. When heated with a sugar, the copper ions in the reagent are reduced, resulting in a color change that can range from blue to green, yellow, or brick red, depending on the amount of sugar present. This reagent is commonly used in laboratories and educational settings to demonstrate the presence of carbohydrates in various substances. The test is simple and effective, making it a popular choice for both scientific research and teaching purposes.