Preparation of bismuth oxynitrate
Bismuth salts in aqueous solution undergo partial hydrolysis very readily. In presence of a considerable amount of free acid, the Bi3+ ion is capable of existence in solution; but with decreasing quantities of acid the tendency to hydrolyze increases, and the basic salt of bismuth, which is only slightly soluble, separates.
The reaction equation does not represent an actual composition of bismuth oxynitrate. The formulas like Bi5O(OH)9(NO3)4, or Bi6O4(OH)4(NO3)6 · 4H2O which represents BiONO3 · H2O are more accurate.
42 grams of crystallized bismuth nitrate pentahydrate (Bi(NO3)3 · 5H2O) are dissolved without heating in 10 ml of 6 N (~30%) nitric acid and 20 ml of water. This solution is poured into 2 liters of cold water with thorough stirring. The obtained precipitate are left to completely settle, and as soon as this has occurred, the solution is filtered. The bismuth oxynitrate is quickly washed on the filter with 20 ml of water and dried. The filtrate contains considerable quantities of bismuth ions, which can be conveniently saved as oxide by precipitating with sodium carbonate.
Synthetic inorganic chemistry, by A. A. Blanchard, 314-315, 1936
Bismuth nitrate oxide, Bismuth(III) oxynitrate, Bismuth(III) subnitrate, Bismuth(III) nitrate basic, 10334_RIEDEL, B0426_SIAL, 95379_FLUKA, MolPort-027-720-479, 10334_SIAL, 310646_SIAL, AKOS015903920, U060, I14-17794