Sodium oxalate is primarily used in analytical chemistry as a standard for calibrating and testing the strength of potassium permanganate solutions in titrations. It acts as a reducing agent in these reactions, allowing for precise measurement of oxidizing agents. In the textile industry, it is employed as a mordant to help fix dyes onto fabrics, ensuring colorfastness and improving dye uptake. Additionally, sodium oxalate is used in the purification of certain chemicals, where it helps precipitate calcium ions from solutions, aiding in the removal of impurities. It also finds application in the manufacturing of specialty chemicals and as a component in certain cleaning agents for its ability to bind metal ions.