... powdered crystals, specific gravity1.532(17 ), easily absorbs moisture, and forms a cake, soluble in water, and the solubility varies as ... the National StandardNN4CL(as dry basis), %99.5minMoisture %0.5maxResidue in ignition %0.4maxFe %0.0009maxPb %0.0005maxSO4 %0.02maxPH ... crystals, specific gravity 1.532(17 )easily absords moisture, and forming a cake, soluble in water, and the solubility varies ...