This stabilized solution of ammonium iron(II) sulfate (Mohr's salt), at 200 g/L in water with 1% aluminum chips to prevent oxidation, is used as a primary standard in redox titrations, particularly for standardizing potassium permanganate and potassium dichromate solutions. Its stability and well-defined composition make it ideal for accurate concentration determinations in analytical chemistry. Also employed in educational laboratories for teaching volumetric analysis due to its reliable reactivity and ease of handling. Additionally, it serves in the preparation of iron-containing reagents and in some industrial processes involving iron deposition or catalysis.