Bismuth Subnitrate
(biz' muth sub nye' trate).
Bi5O(OH)9(NO3)4
![]() ![]() ![]() ![]() ![]() Bismuth hydroxide nitrate oxide Bi5O(OH)9(NO3)4. Bismuth hydroxide nitrate oxide Bi5O(OH)9(NO3)4 ![]() ![]() ![]() » Bismuth Subnitrate is a basic salt that contains the equivalent of not less than 79.0 percent of bismuth trioxide (Bi2O3), calculated on the dried basis.
Packaging and storage—
Preserve in well-closed containers.
Identification—
It responds to the tests for Bismuth
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Loss on drying
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Carbonate—
Add 3 g to 3 mL of warm nitric acid: no effervescence occurs. Pour the solution into 100 mL of water: a white precipitate forms. Filter, evaporate the filtrate on a steam bath to 30 mL, again filter the liquid, divide the latter filtrate into portions of 5 mL each, and use these several portions in the tests for Chloride, Sulfate, Copper, Lead, and Silver.
Chloride
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Sulfate
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Limit of ammonium salts—
Boil about 100 mg with 5 mL of 1 N sodium hydroxide: the vapor does not turn moistened red litmus paper blue.
Arsenic, Method I
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Copper—
To a 5-mL portion of the test liquid retained in the test for Carbonate add a slight excess of 6 N ammonium hydroxide: the liquid does not exhibit a bluish color.
Lead—
Mix a 5-mL portion of the test liquid retained in the test for Carbonate with an equal volume of 2 N sulfuric acid: the liquid does not become cloudy.
Silver—
To a 5-mL portion of the test liquid retained in the test for Carbonate add hydrochloric acid, dropwise: no precipitate is formed that is insoluble in a slight excess of hydrochloric acid, but that is soluble in 6 N ammonium hydroxide.
Limit of alkalies and alkaline earths—
Boil 1.0 g with 20 mL of a mixture of equal volumes of 6 N acetic acid and water, cool, and filter. Add 2 mL of 3 N hydrochloric acid, precipitate the bismuth by the addition of hydrogen sulfide, boil the mixture, and filter it. Add 5 drops of sulfuric acid to the filtrate, evaporate to dryness, and ignite to constant weight: the weight of the residue does not exceed 5 mg (0.5%).
Assay—
Transfer about 400 mg of Bismuth Subnitrate, accurately weighed, to a 250-mL beaker. Add 5 mL of water, then add 2 mL of nitric acid, and warm, if necessary, to effect solution. Dilute with water to 100 mL, add 0.3 mL of xylenol orange TS, and titrate with 0.05 M edetate disodium VS to a yellow endpoint. Each mL of 0.05 M edetate disodium is equivalent to 11.65 mg of Bi2O3.
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
USP38–NF33 Page 2451
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