Basic mercury nitrate

Mercury(II) nitrate solution yellow precipitate of basic mercury(II) sulphate ... 

Although the oxide dissolves in adds, it is only weakly basic. In aqueous solution, Hg(II) salts that are ionized (e.g. Hg(N03)2 and HgS04) are hydrolysed to a considerable extent and many basic salts are formed, e.g. HgO HgCl2 and [0(HgCl)3]Cl (a substituted oxonium salt). Solid Hg(OH)2 is unknown. However, [Hg(0H)][N03] H2O (hydrated basic mercury(II) nitrate ) can be isolated. In the solid state, this contains zigzag chains (23.90) to which H2O molecules are loosely connected. 

Unfortunately, the yield of MF is too low (only about 5 %) because the majority of the mercuric salt of nitromethane is converted into a basic mercury salt of formhydroxamic acid (also an explosive). This mercury salt cannot be converted into MF [2]. The nitromethane itself can also be converted into fulminic acid by nitrosation with nitrous acid to form nitroformaldehyde oxime. It further decomposes (by heating in water or nitric acid) to fulminic acid which is trapped with mercury nitrate as mercury fulminate [2]. 

Lead is reported to be almost imique in not forming compounds of this tA pe, basic lead nitrate and chloride being the principal products formed when aqueous hexamethylenetetramine solutions are reacted with lead nitrate and lead chloride, respectively - . Complexes are reported ivith salts of lithium, sodium, potassium, copper,. silver, gold, magnesium, calcium, strontium, barium, zinc, cadmium, mercury, aluminum, titanium, lanthanum, cerium, neodymium, yttrium, erbium, thorium, tin, antimcnj, bismuth, chromium, molybdenum, tungsten, uranium, manganese, iron, cobalt, nickel, platinum, and palladium -... 

Mercurous Nitrate. Mercurous nitrate [10415-75-5] Hg2N20 or Hg2(N02)2, is a white monoclinic crystalline compound that is not very soluble in water but hydrolyzes to form a basic, yellow hydrate. This material is, however, soluble in cold, dilute nitric acid, and a solution is used as starting material for other water-insoluble mercurous salts. Mercurous nitrate is difficult to obtain in the pure state directly because some mercuric nitrate formation is almost unavoidable. When mercury is dissolved in hot dilute nitric acid, technical mercurous nitrate crystallizes on cooling. The use of excess mercury is helpful in reducing mercuric content, but an additional separation step is necessary. More concentrated nitric acid solutions should be avoided because these oxidize the mercurous to mercuric salt. Reagent-grade material is obtained by recrystaUization from dilute nitric acid in the presence of excess mercury. 

To date, a few methods have been proposed for direct determination of trace iodide in seawater. The first involved the use of neutron activation analysis (NAA) [86], where iodide in seawater was concentrated by strongly basic anion-exchange column, eluted by sodium nitrate, and precipitated as palladium iodide. The second involved the use of automated electrochemical procedures [90] iodide was electrochemically oxidised to iodine and was concentrated on a carbon wool electrode. After removal of interference ions, the iodine was eluted with ascorbic acid and was determined by a polished Ag3SI electrode. The third method involved the use of cathodic stripping square wave voltammetry [92] (See Sect. 2.16.3). Iodine reacts with mercury in a one-electron process, and the sensitivity is increased remarkably by the addition of Triton X. The three methods have detection limits of 0.7 (250 ml seawater), 0.1 (50 ml), and 0.02 pg/l (10 ml), respectively, and could be applied to almost all the samples. However, NAA is not generally employed. The second electrochemical method uses an automated system but is a special apparatus just for determination of iodide. The first and third methods are time-consuming. 

Mercury(I) nitrate is acidic in solution. Its aqueous solution hydrolyzes on standing forming a yeUow precipitate of the basic nitrate, Hg2(N03)(0H). This precipitation occurs more rapidly when diluted with water and warmed. Sufficient nitric acid in the solution suppresses hydrolysis. 

Beside this basic method of manufacturing mercury fulminate, which is widely practised, there are alternate processes. Angelico [11] recognized that mercury fulminate is formed by treating a mercury solution in an excess of nitric acid with a concentrated aqueous solution of malonic acid in the presence of a small amount of sodium nitrate. The reaction results in a considerable rise of temperature, C02 evolution and the precipitation of the fulminate (L. W. Jones [12]). 

Basic acotate of lead oaused a brownish turbidity Bubnitrate of mercury produced a greyish opalescence nitrate of mercury gave a similar, but less decisive reaction chloride of mercury occasioned no change iodine scarcely tinged the menstruum.—Pharmaceutical Journal. 

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. 

P. C. Ray and 8. C. Mukherjee found the degree of ionization to be 0-11 for a mol of the salt in 32 litres. P. C. Ray and N. Dhar found that if the aq. soln. be kept in a closed vessel for some time, some of the mercuric nitrite forms mercurous nitrate and a basic salt is formed thus in 3 weeks, a soln. of sp. gr. 1-065 contained mercuric mercurous mercury as 13-7 1. P. C. Ray and N. Dhar found that the conductivity measurements of aq. soln. of mercurous nitrite agree with the assumption that a complex Hg2(N02) 5-ion is present this corresponds with mercurosic nitrite, HgN02.2Hg(N02)2. For a dilution v=187, A—62-33, and when c=561, A=80-10. With dil. soln., hydrolysis occurs. If the aq. soln. be sealed up in an... 

H. L. Wells, and H. Klinger s basic nitrates of lead, cadmium, zinc, and mercury were shown by G. Watson to fall in line with this hypothesis but F. Meissner could not support it, and F. W. Kuster and R. Kremann showed that the f.p. curve of binary mixtures of nitric acid and water invalidates H. Erdmann s conclusions— vide infra. 

The fluoride of dipositive mercury stands apart from the other halides, being far more like the nitrate and perchlorate. The Hg—F bonds in the solid state are predominantly ionic, and upon dissolving HgF2 in water, the very acidic Hg2 " ion reacts with the basic water molecules, yielding both a basic fluoride and HgO. 

IV.18 NITRATES, NO3 Solubility All nitrates are soluble in water. The nitrates of mercury and bismuth yield basic salts on treatment with water these are soluble in dilute nitric acid. 

Nitrates, chlorates, acetates, manganates, and permanganates are all soluble exceptions are a few basic nitrates (e.g. Bi and Sb) and basic acetates (e.g. Fe) silver and mercury(I) acetates are sparingly soluble. 

---