Ammoniated Mercury
Hg(NH2)Cl 252.07

Mercury amide chloride.
Mercury amide chloride [10124-48-8].
» Ammoniated Mercury contains not less than 98.0 percent and not more than 100.5 percent of Hg(NH2)Cl.
Packaging and storage— Preserve in well-closed, light-resistant containers.
A: A 0.1-g portion is soluble, with the evolution of ammonia, in a cold solution of 1 g of sodium thiosulfate in 2 mL of water. When this solution is heated gently, a rust-colored mixture is formed, from which a red precipitate is obtained on centrifugation. If the solution is strongly heated, a black mixture forms.
B: When heated with 1 N sodium hydroxide, it becomes yellow, and ammonia is evolved.
C: A solution in warm acetic acid yields with potassium iodide TS a red precipitate, which is soluble in an excess of the reagent. The solution yields a white precipitate with silver nitrate TS.
Residue on ignition 281: not more than 0.2%.
Mercurous compounds— Dissolve 2.5 g in 25 mL of warm hydrochloric acid, filter through a tared filtering crucible, wash with water, and dry at 60 to constant weight: the weight of the residue does not exceed 5 mg (0.2%).
Assay— Mix about 0.25 g of Ammoniated Mercury, accurately weighed, with about 10 mL of water. Add 3 g of potassium iodide, mix occasionally until dissolved, and add about 40 mL of water. Add methyl red TS, and titrate with 0.1 N hydrochloric acid VS. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N hydrochloric acid is equivalent to 12.60 mg of Hg(NH2)Cl.
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Topic/Question Contact Expert Committee
Monograph Behnam Davani, Ph.D., M.B.A.
Senior Scientific Liaison
(SM12010) Monographs - Small Molecules 1
USP35–NF30 Page 3813