cas;no:10039-32-4 7558-79-4 properties: white or colorless crystalline free flowing solid, efflorescent in air, easily soluble in water, but insoluble in alcohol, its water solution is slightly alkaline, relative density at 1.63, melting point at 34.6 . uses: used as a fire-preventio agent for fabric, timber, and paper, also as water softening agent for boiler, food additive, buffering agent, solder, tanning agent, etc.