Property: Soluble in water and able to integrate with various metal ions. It has chelating ability to calcium containing hard water in various pH ranges and concentrations, with the highest potency at pH ≥ 8. Complex with calcium ions in a 1:1 molar ratio, it has good thermal stability in water and even does not decompose in superheated water, making it an effective hard water softener. Application: Used as a water softener, synthetic rubber catalyst, acrylic polymerization termination agent, printing and dyeing assistant, detergent assistant, used as a color sensitive material washing and processing bleach fixing solution, etc. It is also used for titration in chemical analysis and can accurately titrate various metal ions