?It is colourless column crystal, odorless, slightly deliquescence. The relative density is 2.04 and melting point is 60oC. It is easily soluble in water but insoluble in ethahol. If heated below 100oC, it can dissolve in crystal water and convert to monohydrate salt. When heated to 100oC, it will lose crystal water and change its anhydrous substances, which will become sodium metaphosphate if it's continue to be heated.