Chromic Arsenite, CrNaO₃

Chromic Arsenite, CrNaO₃, was described by Neville as a dark green powder which separated when a concentrated solution of pure chromic acid was boiled for some time with a saturated solution of arsenious acid. Stavenhagen could not obtain it by this method. It may be obtained, however, by digesting a concentrated solution of chromic sulphate with potassium tetrarsenite; a precipitate containing the arsenite and arsenious oxide slowly forms, and the former may be isolated by dissolving in hydrochloric acid and reprecipitating with aqueous ammonia. It is obtained as a dark green mass, soluble in potassium hydroxide solution and in dilute acids.