Mercurous nitrate

REACTIONS AND IDENTIFICATION 325 drop. JNote that the white precipitate of silver salts turns black (showing the presence of silver cyanide). Now add an excess of mercurous nitrate the black precipitate redissolves, but the silver halide remains undissolved. 

Mercuric nitrite reaction (Millon s reaction). Dissolve a very small crystal of tyrosine in i ml. of water, add 1-2 drops of mercuric nitrate solution, and I drop of dil. HjSO, and then boil. Cool, add i drop of sodium nitrite solution and warm again a red coloration is obtained. 

Must of the ammonia is evolved in about I hour. The vapour should be tested periodically for the presence of ammonia with mercurous nitrate paper. If traces are still present after 3-4 hours, the solution should be steam distilled for 30 minutes. 

Primary aromatic amides are crystaUine sohds with definite melting points. Upon boiling with 10-20 per cent, sodium or potassium hydroxide solution, they are hydrolysed with the evolution of ammonia (vapour turns red htmus paper blue and mercurous nitrate paper black) and the formation of the alkah metal salt of the acid ... 

Benzene and some of its derivatives react with solutions of mercuric nitrate in concentrated nitric acid to give nitrophenols. These reactions, known as oxynitrations may proceed by mercuration followed by nitroso-demercuration the resulting nitroso compound becomes a diazonium compound and then a phenol, which is nitrated. ... 

To do the reaction the chemist places a flask in an ice bath on top of the stirplate and into it is added lOOmL acetonitrile (CH3CN) and 65g anhydrous mercuric nitrate. A small separatory funnel that has 33g of safrole or 24g allylbenzene is placed over the flask so that everything looks just like that of fig. 9. The safrole is then slowly dripped in so that the temperature stays between 20-28 C. A yellow precipitate will form as the mercuric nitrate latches on to the safrole. After the addition is finished, the ice bath is removed and the solution stirred at room temperature for 1 hour. 

The acetonitrile and mercuric nitrate amounts remain the same except they are to be accompanied by 12.6g of fuming nitric acid (see chemicals section) in the reaction flask. Then, with cooling, the safrole or allylbenzene is added just like before. The reaction is immediate and takes no more than 20 minutes of stirring after which lOOmL ice cold dH20 is slowly added. Next, with vigorous stirring, saturated sodium chloride solution is slowly added until a pronounced precipitate forms. This yellowish mass is the chloride. 

Yeesh That was what Strike wrote last year. And the sad truth is that it did not work The reason why is the way Strike proposed getting anhydrous mercuric nitrate. The baking of commercially available mercuric nitrate monohydrate was actually destroying most of the compound. Aside of that this recipe works It really does. 

So what can be done about the mercuric nitrate problem The authors in the original paper from which this recipe came from, clearly call for an amount of mercuric nitrate that is exactly equal... 

Surely one would hope not. What if one just used the mercuric nitrate monohydrate that is at hand. One s only real concern would be if the monohydrate water would interfere with the acetonitrile in a competing oxymercuration reaction. But could it really considering the massive excess of acetonitrile present All Strike can say is that someone, somewhere is gonna try it. And Strike would really, really like to hear about it. 

Mercurous nitrate, HgNOj mix 1 part of HgNOj, 20 parts of HjO, and 1 part of HNO3. 

The second method of preparation involves precipitation from a cold acidic solution of mercurous nitrate. Mercurous chloride is isolated after washing in a manner similar to the chamber method described. This product, which generally contains small amounts of occluded sodium nitrate, is satisfactory as a technical-grade material. Difficulty may be encountered in having it pass NF or reagent-grade specifications (see Fine chemicals). 

Mercurous Bromide. Mercurous hi.omide[15385-58-7] Hg2Br2, is a white tetragonal crystalline powder, very similar to the chloride, and prepared in much the same way, ie, by the direct oxidation of mercury by bromine or by precipitation from mercurous nitrate by sodium bromide. It is sensitive to light, less stable than the chloride, and is not of appreciable commercial importance. 

Mercuric Bromide. Mercuric hi.omide[7789-94-7] HgBr2 is a white crystalline powder, considerably less stable than the chloride, and also much less soluble in water (0.6% at 25°C). Therefore, it is prepared easily by precipitation, using mercuric nitrate and sodium bromide solution. Drying of the washed compound is carried out below 75°C. Mercuric bromide has a few medicinal uses. 

Mercurous Iodide. Mercurous iodide [7783-30 ] Hg2l2, is a bright yellow amorphous powder, extremely insoluble in water and very sensitive to light. It has no commercial importance but may be prepared by precipitation, using mercurous nirate and potassium iodide. Care must be taken to exclude mercuric nitrate, which may cause the formulation of the water-insoluble mercuric iodide. 

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. 

Mercuric Nitrate. Mercuric nitrate [10045-94-0] Hg(N02)2, is a colorless dehquescent crystalline compound prepared by the exothermic dissolution of mercury in hot, concentrated nitric acid. The reaction is complete when a cloud of mercurous chloride is not formed when the solution is treated with sodium chloride solution. The product crystallizes upon cooling. Mercuric nitrate is used in organic synthesis as the starting material and for the formulation of a great many other mercuric products. 

Red mercuric oxide generally is prepared in one of two ways by the heat-induced decomposition of mercuric nitrate or by hot precipitation. Both methods require careful control of reaction conditions. In the calcination method, mercury and an equivalent of hot, concentrated nitric acid react to form... 

In the hot precipitation method, sodium carbonate solution is added slowly to a refluxing solution of mercuric chloride, followed by an additional reflux period of 1 to 2 h. The washed precipitate is then dried. A variation allows the substitution of mercuric nitrate for the chloride if substantial quantities of sodium chloride are used. Sodium hydroxide, ia the presence of sodium carbonate, is the precipitant. 

Mercurous Sulfate. Mercurous s Ai2LX.e[7783-36-0] Hg2S04, is a colodess-to-shghfly-yellowish compound, sensitive to light and slightly soluble ia water (0.05 g/100 g H2O). It is more soluble ia dilute acids. The compound is prepared by precipitation from acidified mercurous nitrate solution and dilute sulfuric acid. The precipitate is washed with dilute sulfuric acid until nitrate-free. Its most important use is as a component of Clark and Weston types of standard cells. 

Chloride. Chloride is common in freshwater because almost all chloride salts are very soluble in water. Its concentration is generally lO " to 10 M. Chloride can be titrated with mercuric nitrate. Diphenylcarbazone, which forms a purple complex with the excess mercuric ions at pH 2.3—2.8, is used as the indicator. The pH should be controlled to 0.1 pH unit. Bromide and iodide are the principal interferences, whereas chromate, ferric, and sulfite ions interfere at levels greater than 10 mg/L. Chloride can also be deterrnined by a colorimetric method based on the displacement of thiocyanate ion from mercuric thiocyanate by chloride ion. The Hberated SCN reacts with ferric ion to form the colored complex of ferric thiocyanate. The method is suitable for chloride concentrations from 10 to 10 M. 

Impurities in bromine may be deterrnined quantitatively (54). Weighing the residue after evaporation of a bromine sample yields the total nonvolatile matter. After removing the bromine, chloride ion may be deterrnined by titration with mercuric nitrate, and iodide ion by titration with thiosulfate water and organic compounds may be detected by infrared spectroscopy sulfur may be deterrnined turbidimetricaHy as barium sulfate and heavy metals may be deterrnined colorimetricaHy after conversion to sulfides. 

The reactivity of mercury salts is a fimction of both the solvent and the counterion in the mercury salt. Mercuric chloride, for example, is unreactive, and mercuric acetate is usually used. When higher reactivity is required, salts of electronegatively substituted carboxylic acids such as mercuric trifiuoroacetate can be used. Mercuric nitrate and mercuric perchlorate are also highly reactive. Soft anions reduce the reactivity of the Hg " son by coordination, which reduces the electrophilicity of the cation. The harder oxygen anions leave the mercuric ion in a more reactive state. Organomercury compounds have a number of valuable synthetic applications, and these will be discussed in Chapter 8 of Part B. 

Merkuri-jodid, n. mer curic iodide, mercury (II) iodide, -nitrat, n. mercuric nitrate, mercury-(II) nitrate. -oxyd, n. mercuric oxide, mercury (II) oxide, -rhodanid, n. mercuric thiocyanate, mercury(II) thiocyanate, -salz, n. mercuric salt, mercury (II) salt, -sulfati n. mercuric sulfate, mercury (II) sulfate, -sulfidt ti. mercuric sulfide, mercury (II) sulfide. -sulfozyamd, n. mercuric thiocyanate. 

Merkuro-. mercurous, mercury (I), -azetat, n. mercurous acetate. mercury(I) acetate, -chlorld, n. mercurous chloride, mercury(I) choride. -chrom, n. (Pharm.) mercuro chrome, -jodid, n. n ercurous iodide, mer-cury(I) iodide. -nitrat, n. mercurous nitrate, mercury(I) nitrste. -oxyd, n. mercurous oxide, mercury(I) oxide, -salz, n. mercurous salt, mercury (I) salt, -sulfat, n. mercurouasulfate, mercury(I) sulfate, -sulfid, n. mercurous sulfide, mercury(I) sulfide, -verbindung, /. mercurous compound, mercury (I) compound. 

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