Features Specifications:H acid   H-acid( 1-Amino-8-naphthol-3,6-disulfonic acid monosodium salt )  Structural formula :  Molecular formula : C10H8O7NS2Na Molecular weight : 341.3  Cas No.:90-20-0 Main Uses: used to produce all kinds of azo dyes, used to dye wools, textiles, papers and paper textiles; also used to synthesize pharmaceutical. Properties :  Items Specification Appearence Greyish white to light grey powder H-acid monosodium salt%≥ 85 Content of the alkali insolubles (100%) % ≤ 0.2 Allochromatic acid disodium salt(100%) % ≤ 2 T-acid disodium salt(100%) % ≤ 0.5 Moisture Content % ≤ 5 Physical and Chemical Properties: (1) the solubility in water is 0.17% (20°C); (2)the solubility in water is 2.40% (60C°C); (3)insoluble in alcohol and aether; (4)soluble in solutions of alkali, sodium carbonate and ammonia; (5)the dilute solution of H-acid appears blue red fluorescence; (6)H-acid can couple in both acid and alkali condition; (7)a. the alkali solution of H-acid fast becomes dark in air; b. to produce yellow crystalline diazo compound when reacting with nitrous acid; c. diazo compounds are soluble in soda and alkali solution; d. appears light violet when dissolving in soda solution, e. appears dark green when dissolving in alkali solution. (2) Package:Net weight 25kgs are packed in one PE bag and the kraft paper bag with PE liner outside