Sodium tripolyphosphate:
White powder, apparent density 0.35-0.90g/cm3, melting point 622c. Soluble in water. Aqueous solutions are alkaline and 1% aqueous solutions have a PH of 9.7. Hydrolyzed into phosphite in water, it has good complexing ability of metal ions. It can complex with calcium, magnesium, iron and other metal ions to form a soluble complex. It softens hard water. As an inorganic surfactant, it has some properties of organic surfactant.