Monosodium Phosphate MSP 98% CAS 7558-80-7 is colorless crystal, odorless, slightly deliquescent. The relative density is 2.04 and melting point is 60. It is easily soluble in water but insoluble in ethahol. If heated below 100â??, it can dissolve in crystal water and convert to monohydrate salt. When heated to 100, it will lose crystal water and change its anhydrous substances, which will become sodium metaphosphate if it's continue to be heated.