Used in analytical chemistry for redox titrations, particularly in determining the concentration of oxidizing agents. It serves as a stable source of ferrous ions (Fe²⁺) that react quantitatively with oxidants like potassium dichromate or permanganate. Commonly applied in water and wastewater analysis to measure chemical oxygen demand (COD). Also utilized in educational laboratories for teaching titration techniques due to its stability and well-defined reactivity. Suitable for standardizing potassium permanganate and cerium(IV) sulfate solutions.