White or pale yellow, transparent rhombic crystal. 692g / cm3. The melting point is 795 ℃. Boiling point 1155 ℃ (sublimation). It turns yellow when heated and recovers when cold. Even below the melting point, there is a significant sublimation phenomenon. Insoluble in water, soluble in ammonia and strong alkali. Sodium molybdate in Jiangsu Province reacts with alkali solution and many metal oxides to form molybdate and polymolybdate.

Sodium molybdate in Jiangsu Province is used as a high-efficiency flame retardant and smoke suppressant, especially for chlorine containing adhesives. The reference dosage of 0.5 ~ 5.0 phr can reduce the tobacco yield by 30% ~ 80% and increase the oxygen index by 10% ~ 20%. The mixture of molybdenum compounds with copper oxide, iron oxide, cadmium oxide and zinc oxide has synergistic effect, and its smoke suppression effect is better than that of single MoO3. The flame retardant and smoke suppressant of sodium molybdate manufacturers in Jiangsu Province are mostly the mixture of molybdenum oxide and ammonium molybdate.