Mercuric orthoarsenite

Mercury Arsenites.—Mercurous Orthoarsenite, Hg3As03, may be obtained by treating a solution of mercurous nitrate with one of sodium orthoarsenite6 or with a solution of arsenious oxide in 50 per cent, alcohol 6 in the latter case the mercurous nitrate solution should be acidified with nitric acid and sufficient alcohol added to produce a slight turbidity. The precipitate is pale yellow, but rapidly turns brown on exposure to air. It is slightly soluble in water, being slowly decomposed with separation of mercury. It is also decomposed by hydroxides and carbonates of alkali metals and of barium, and by ammonia. It dissolves in acids, but when these are dilute, basic salts gradually separate. 

Mercuric Orthoarsenite, Hg3(As03)2, is precipitated in an impure state when an aqueous solution of mercuric chloride is treated with a solution of arsenious oxide in 50 per cent, alcohol. The salt is unstable and loses arsenious oxide at 150° C. It is slowly reduced to mercury and mercurous hydroxide by water, in which it is sparingly soluble, and by aqueous alkalis and ammonia. It dissolves in acids, but with sulphuric acid a basic sulphate is formed. 

---

See also in sourсe #XX -- [ ]

---