Iron(II) Ethylenediammonium Sulfate Tetrahydrate is primarily used in analytical chemistry as a reagent for the determination of nitrate concentrations in various samples. It is particularly effective in colorimetric methods, where it reacts with nitrates to produce a distinct color change, allowing for precise quantification. This chemical is also utilized in the preparation of complexometric titrations, where it serves as a source of iron ions to form stable complexes with certain ligands. Additionally, it finds application in research laboratories for synthesizing coordination compounds and studying their properties. Its stability and solubility in water make it a convenient choice for these purposes.