Mercury nitrite

Mercuric and mercurous nitrates have the same oxidising properties as nitrates. The first has been involved in accidents with phosphine (formation of a complex, which detonates on impact) and alkaline cyanides. In the latter case, it is assumed that the danger arises from the formation of mercury nitrite, which is highly unstable in one particular accident the use of an apparatus with a narrow neck aggravated the effect, causing an effect of confinement. The second nitrate led to more or less strong detonations with carbon (red-hot) and phosphorus (on impact). 

The reaction is exothermic, and multitubular reactors are employed with indirect cooling of the reactor via a heat transfer medium. A number of heat transfer media have been proposed to carry out the reactor cooling, such as hot oil circuits, water, sulfur, mercury, etc. However, the favored heat transfer medium is usually a molten heat transfer salt which is a eutectic mixture of sodium-potassium nitrate-nitrite. 

Steam is by far the most widely used medium, useful up to about 475 K. Up to about 700 K organic liquids such as the dowtherms and mineral oil may be used. Mercury and molten salts, such as the eutectic mixture of sodium nitrite, sodium nitrate and potassium nitrate may be used up to 875 K, while above this temperature air and flue gases must be used. 

Fit a three necked 250 ml. flask with a central rubber-sleeved or mercury-sealed stirrer, c/. Fig. 23(c), p. 45, where only two necks are shown, and with a thermometer the bulb of which reaches as near the bottom of the flask as the stirrer allows the third neck will carry at first a dropping-funnel and later a reflux condenser. Place 20 g. (19-5 ml.) of ethyl acetoacetate and 45 ml. of glacial acetic acid in the flask and by ice-water cooling adjust the temperature of the stirred mixture to 5 -7° maintain this temperature whilst adding a solution of 5 4 g. of sodium nitrite in 8 ml. of water slowly from the dropping-funnel during 15 minutes. Continue the stirring for 20-30 minutes, and then... 

Mercury(II) cyanide Fluorine, hydrogen cyanide, magnesium, sodium nitrite... 

Mercury, chlorine, calcium hypochlorite, iodine, bromine or hydrogen fluoride Acids, metal powders, flammable liquids, chlorates, nitrites, sulphur, finely-divided organics or combustibles Nitric acid, hydrogen peroxide... 

The above nitrite (0.93 g) is dissolved in 40 ml of dry benzene and irradiated for 1 hr at 0-5° in a nitrogen atmosphere with two 200 Watt mercury lamps. The resulting suspension is concentrated and filtered to give 0.59 g of essentially pure 20a-hydroxy-18-oximinopregn-4-en-3-one as a benzene solvate mp 110-125°. Recrystallization from acetone gives an analytical sample mp 184-186° [a] 149° (CHCI3). 

Mixtures of sodium nitrite and various cyanides [1] explode on heating, including potassium cyanide [2], potassium hexacyanoferrate(III), sodium pentacyanonitro-sylferrate(II) [3], potassium hexacyanoferrate(II) [4], or mercury(II) cyanide [5], Such mixtures have been proposed as explosives, initiable by heat or a detonator [5],... 

Atomic hydrogen is a powerful reducing agent, even at room temperature. For example, it reacts with the oxides and chlorides of many metals, including silver, copper, lead, bismuth, and mercury, to produce the free metals. It reduces some salts, such as nitrates, nitrites, and cyanides of sodium and potassium, to the metallic state. It reacts with a number of elements, both metals and nonmetals, to yield hydrides such as NH3, NaH, KH, and PH3. Sulfur forms a number of hydrides the simplest is H2S. Combining with oxygen, atomic... 

Absorptive cathodic stripping voltammetry has been used [151,152] to determine nanomolar levels of nitrite in seawater. The nitrite is derivatised by diazotisation with sulfanilamide and coupled with 1-naphthylamine to form an azo dye. The dye adsorbs onto a mercury drop electrode and its reduction is fully reversible. The concentration of dye is linearly related to concentration of nitrite in the range 0.3-200 nM. Down to 0.3 nM nitrite can be determined in seawater for an adsorption time of 60 seconds. 

Airey et al. [8] have described a method for removing sulfide prior to the determination of these anions in anoxic estuarine waters. Mercury(II) chloride was used to precipitate free sulfide from samples of anoxic water. The sulfide-free supernatant solution was used to estimate sulfide by measuring the concentration of unreacted mercury(II), as well as to determine sulfate, inorganic phosphate, and nitrate by spectrophotometric methods, in which sulfide interferes. Sulfide concentrations in the range 0.5-180 000 ig/l sulfur could be measured, while the lower limits for sulfate, ammonia, nitrite, and inorganic phosphate were 0.024, -1.0 and 1 xg/l, respectively. 

Mercury(II) cyanide Mercury(I) nitrate Mercury(II) nitrate Fluorine, hydrogen cyanide, magnesium, sodium nitrite Phosphorus Acetylene, aromatics, ethanol, hypophosphoric acid, phosphine, unsaturated organic compounds... 

In a similar procedure [32] the sediment is wet oxidised with dilute sulphuric acid and nitric acids in an apparatus in which the vapour from the digestion is condensed into a reservoir from which it can be collected or returned to the digestion flask as required. The combined oxidised residue and condensate are diluted until the acid concentration is IN and nitrate is removed by addition of hydroxylammonium chloride with boiling. Fat is removed from the cooled solution with carbon tetrachlodithizone in carbon tetrachloride. The extract is shaken with 0.1M hydrochloric acid and sodium nitrite solution and, after treatment of the separated aqueous layer with hydroxylammonium chloride a solution of urea and then EDTA solution are added to prevent subsequent extraction of copper. The liquid is then extracted with a 0.01% solution of dithizone in carbon tetrachloride and mercury estimated in the extract spectrophotometrically at 485nm. 

In the analysis of water, the use of ethanol to remove more than traces of nitrate or nitrite ion may lead to formation of fulminic acid, and if mercury(II) is used as a catalyst, explosive mercury fulminate may be formed. 

Several explosive salts including the acetylide, azide, borate, bromate, chlorate, chromate, iodate (and ammonium iodate double salt), nitrite, perchlorate (and ammonium perchlorate double salt), periodate, permanganate, picrate and trinitrobenzoate were prepared. The 3 latter salts and the acetylide, azide and bromate are impact-sensitive detonators [1], It appears probable that many of the explosively unstable compounds [2], formed in various ways from interaction of mercury or its compounds with ammonia or its salts, may have the common polymeric structure now recognised for Millon s base [3], This is a silica-like network of N+ and Hg in 4- and 2-coordination, respectively, with OH and water in the interstitial spaces. Individually indexed compounds are Poly(dimercuryimmonium acetylide)... 

Nitrotetrazole is readily prepared from the diazotization of 5-aminotetrazole in the presence of excess sodium nitrite and is best isolated as the copper salt complex with ethylenediamine. The salts of 5-nitrotetrazole have attracted interest for their initiating properties. The mercury salt is a detonating primary explosive. The amine salts of 5-nitrotetrazole are reported to form useful eutectics with ammonium nitrate. ... 

Aminotetrazole (91) reacts with potassium permanganate in excess aqueous sodium hydroxide to yield the disodium salt of 5-azotetrazole (92). 5-Azotetrazole is unstable and attempts to isolate it by acidification yields 5-hydrazinotetrazole (93). Diazotization of 5-aminotetrazole (91) in the presence of excess sodium nitrite yields 5-nitrotetrazole (94), a powerful explosive whose mercury and silver salts are primary explosives. ... 

---