H Acid

Physical and Chemical Properties:
(1)the solubility in water is 0.17% (20癈);
(2)the solubility in water is 2.40% (60C癈);
(3)insoluble in alcohol and aether;
(4)soluble in solutions of alkali, sodium carbonate and ammonia;
(5)the dilute solutiono f 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, appears dark green when dissolving in alkali solution.
Main Uses: used to produce all kinds of azo dyes, used to dye wools, textiles, papers and paper textiles; also used to synthesize pharmaceutical.