... apt to absorb humidity in the open air to deliquescent; Soluble in water but insoluble in ethanol, and at 25 ,its solubility ... .0003 7PH Value10.0-10.710.0-10.78Ortho Phosphatepass Water-soluble, colorless crystals; dehydrates below 300.C, melts at 1090.C ... form stable chelates with Ca2+ and Mg2+ in hard water to soften hard water, to increase washing capability, to remove dirt, and ...