Used in the synthesis of azo dyes and pigments, particularly for textiles, leather, and paper, due to its ability to form stable colored compounds. Employed in the production of indicators like methyl orange for pH testing in laboratories. Serves as an intermediate in pharmaceutical manufacturing, including certain sulfa drugs. Applied in electroplating processes to improve metal surface finish and adhesion. Also utilized in analytical chemistry for detecting nitrites and other compounds through diazotization reactions.