Formula of Benedict's reagent
Benedict's reagent is a chemical solution used to test for the presence of reducing sugars, such as glucose, in a given sample.

Composition:
- The formula of Benedict's reagent is CuSO4•5H2O (copper sulfate pentahydrate), Na2CO3 (sodium carbonate), and sodium citrate.
- The copper ions in the CuSO4 are reduced to cuprous ions by the reducing sugar present in the sample.

Preparation:
- To prepare Benedict's reagent, dissolve 17.3 g of copper sulfate pentahydrate and 100 g of sodium carbonate in 500 mL of distilled water.
- Add 173 g of sodium citrate to the solution and bring the total volume to 1 L with distilled water.
- The resulting solution is a deep blue color.

Working principle:
- When Benedict's reagent is heated with a reducing sugar, the cupric ions in the copper sulfate are reduced to cuprous ions, forming a brick-red precipitate of copper (I) oxide.
- The intensity of the color change indicates the concentration of reducing sugars present in the sample.

Application:
- Benedict's reagent is commonly used in laboratory settings to test for the presence of reducing sugars in various food products, such as fruits, milk, and honey.
- The test is based on the reducing properties of sugars, which can donate electrons to other substances, such as the cupric ions in Benedict's reagent.
In conclusion, Benedict's reagent is a crucial tool in biochemical analysis for detecting the presence of reducing sugars, and its formula and preparation are essential for its effective use in various scientific experiments.