Primarily used in chemical synthesis, it serves as a key reagent in the production of various pharmaceuticals and pesticides. In analytical chemistry, it is employed as a sensitive indicator for detecting the presence of iron ions, turning blood red upon reaction. Additionally, it finds application in the textile industry, where it is used in dyeing and printing processes to enhance color fastness. It is also utilized in the manufacturing of photographic chemicals and as a stabilizing agent in some types of photographic emulsions. Furthermore, it plays a role in the creation of artificial mustard oil and in certain metal treatment processes to improve surface properties.