Used in analytical chemistry for redox titrations, particularly to determine the concentration of oxidizing agents such as potassium permanganate or potassium dichromate. It serves as a reducing agent in acid medium, providing reliable and consistent results in volumetric analysis. Commonly applied in water and wastewater testing to measure chemical oxygen demand (COD). Also utilized in pharmaceutical analysis for assay of certain compounds requiring controlled redox conditions. Its standardized solution ensures accuracy in titration procedures where precise electron transfer is critical.