Metal nitrates decomposition

Hence dinitrogen tetroxide (sometimes mixed with an organic solvent) can be used to prepare anhydrous metal nitrates (many heavy metal nitrates are hydrated when prepared in aqueous solution, and they cannot be dehydrated without decomposition). 

Fig. 5. HREM of enclosed silver particles in CNTs. The metallic particles were obtained by electron irradiation-induced decomposition of introduced silver nitrate. Note that the gases produced by the nitrate decomposition have eroded the innermost layer of the tube.

In general, ammonia is evolved before anion breakdown in the decompositions of ammonium metal nitrates [960,961], Decomposition of hydrazonium nitrate [962] obeys second-order kinetics and presumably occurs in a melt. 

Decompose salts containing the catalyst precursors such as metal nitrates, formates, oxalates, or acetates. (Oxides are the usual products of the decomposition process.)... 

See other irradiation decomposition incidents, metal nitrates 4769. Diseleniumdisulfur tetranitride... 

Outside of catalyst preparation, reaction of sucrose with metal nitrates has been used to prepare nanocomposite mixed oxide materials. Wu et al. [46] reported the synthesis of Mg0-Al203 and Y203-Zr02 mixed oxides by reaction of nitrate precursors with sucrose. The resulting powders had smaller particles than those prepared without sucrose. Das [47] used a similar method in the presence of poly vinylalcohol to produce nanocrystalline lead zirconium titanate and metal ferrierites (MFe204, M = Co, Ni, or Zn). The materials prepared using sucrose had smaller crystallites than those made without. Both authors observed an exothermic decomposition of the precursors during calcination. 

Malecki A., Gajerski R., Labus S., Prochowska-Klisch B., and Wojciechowski K.T. 2000. Mechanism of thermal decomposition of d-metals nitrates hydrates. J. Therm. Anal. Calorim. 60 17-23. 

Most nitrates decompose on heating, but here the decomposition is somewhat more complicated. Dissociation into oxides and N205 does not occur because the latter compound further splits into lower oxides of nitrogen and oxygen. The alkali-metal nitrates decompose into nitrites and oxygen. Thus... 

The second metal, for example, the promoter, may also be added by subsequent impregnation of binary sulfide. When a nonreactive promoter precursor, for example, metal nitrate, is used it is necessary to resulfide the impregnated sulfide in order to decompose the precursor. Another variation of this method consists in using reactive promoter precursors that will react with the surface of the binary sulfide. In this case, further treatment of the catalyst may not be required. Good precursors include metal carbonyls and metal alkyls (32, 33). The precursor decomposition approach been most widely applied to the MoS2-based systems. However, it has also been extended to the mixed noble-metal sulfides by Breysse and co-workers (34) at Lyon following the work of Passaretti et al (35). 

Nitrocellulose, treated with different hydrolysing agents such as aqueous solutions of alkalis, does not yield cellulose and the corresponding metal nitrate, but a range of highly variable decomposition products of cellulose as well as of inorganic substances. 

Decomposition of metal nitrates, carbonates, oxides and hydroxides... 

The ways in which metal nitrates, carbonates, oxides and hydroxides decompose can also be discussed in terms of the reactivity series of the metals. The decomposition processes are different, depending on the position of the metal in the reactivity series. 

See other IRRADIATION DECOMPOSITION INCIDENTS, METAL NITRATES... 

Synonyms nitrogen peroxide Formula N02 MW 46.01 CAS [10102-44-0] occurs in the exhausts of automobiles and in cigarette smoke produced by the reaction of nitric acid with metals and decomposition of nitrates or during fire reddish-brown fuming liquid or gas sharp pungent odor liquefies at 21°C solidifies at -9.3°C density of liquid 1.45 at 20°C vapor 1.58 (air= 1) reacts with water to form nitric acid and nitrogen oxide reacts with alkalies to form nitrates and nitrites highly toxic. 

Since the nitrite of a given metal is generally much less stable than the nitrate, the former can appear only as an unstable intermediate in the decomposition of the nitrate. This is particularly true for covalent nitrates. In the case of ionic nitrates, however, both salts may be more or less equally unstable over some temperature range, so that the decomposition reactions can become quite complex. This is particularly so since the salts may be oxidized or reduced by the gaseous decomposition products. For example, N02 produced by the decomposition of the nitrate may oxidize the nitrite ion also formed back to the nitrate. Since the experimental arrangement usually determines the gas-phase composition, reports by different authors frequently conflict. In such cases the common features have been emphasized in this chapter. A consequence of the complexity of most nitrate decompositions is that kinetic studies have usually been restricted to identifying the reactions. Even when rate constants and activation energies are reported it is frequently not clear with which particular reactions they are identified. 

The add has already been discussed (Section 2-12). Nitrates of almost all metallic elements are known. They are frequently hydrated and most are soluble in water. Many metal nitrates can be obtained anhydrous, and a number of these, for example, Cu(N03)2, sublime without decomposition. 

SAFETY PROFILE Moderately toxic by subcutaneous route. Incompatible with metal nitrates, sodium nitrite. When heated to decomposition it emits very toxic fumes of Na20 and SO. See also SODIUM THIOSULFATE and SODIUM THIOSULFATE, PENTAHYDRATE. 

DOT CLASSIFICATION 8 Label Corrosive SAFETY PROFILE Poison by intraperitoneal route. Moderately toxic by ingestion. A human skin irritant. A corrosive irritant to skin, eyes, and mucous membranes. A substance that migrates to food from packaging materials. Violent or explosive reactions with chlorine, metal nitrates + heat, metal nitrites + heat, fuming HNO3. When heated to decomposition it emits very toxic fumes of SOx and NOx. See also SULFONATES. 

OSHA PEL TWA 2 mg(Sn)/m3 ACGIH TLV IW A 2 mg(SnVm3 SAFETY PROFILE Poison by ingestion, intraperitoneal, intravenous, and subcutaneous routes. Experimental reproductive effects. Human mutation data reported. Potentially explosive reaction with metal nitrates. Violent reactions with hydrogen peroxide, ethylene oxide, hydra2ine hydrate, nitrates, K, Na. Ignition on contact with bromine trifluoride. A vigorous reaction with calcium acetylide is initiated by flame. When heated to decomposition it emits toxic fumes of Cl. See also TIN COMPOUNDS. 

Ceda-based oxides can be obtained by the decomposition of some compound precursor, such as hydroxide, nitrate, halides, sulfates, carbonates, formates, oxalates, acetates, and citrates.For example, nanosize or porous cerium oxide particles have been prepared at low temperatures by pyrolysis of amorphous citrate," which is prepared by the evaporation of the solvent from the aqueous solution containing cerium nitrate (or oxalate) and citric acid. In the case of mixed oxides, the precursor containing some cations in the same solid salts is prepared. In the same manner of ceria particles, the precursors complexing some cations with citrates are useful to synthsize ceria-zirconia mixed oxides and their derivatives. Also. Ce02-Ln203 solid solutions, where Ln = La. Pr, Sm. Gd. and Tb, have been synthesized from the precursors obtained by the evaporation of nitrate solutions at 353 K in air from an intimate mixture of their respective metal nitrates. The precursors are dried and then heated at 673 K to remove niU ates, followed by calcination at 1073 K for 12h. 

Plutonium Dioxide in Molten Equimolar Sodium-Potassium Nitrate. The behavior of plutonium dioxide in molten alkali metal nitrates is an area of major concern. Claims that alkali metal plutonates are formed (1, 2, 3, 5, 6) are not substantiated by definitive analytical results. In some cases (5, 6), sodium peroxide was added as an oxidant to either an alkali metal nitrate melt (6) or to an alkali metal hydroxide melt (5). If the temperature is great enough, for example above 700°C, thermal decomposition of the nitrate melt produces peroxide species. Other studies (4, , 12, 17) do not claim formation of a plutonate species, but only state that an insoluble plutonium-containing compound exists. However, in all the references cited, the results were given for mixed uranium-plutonium dioxide definitive analytical results were not given. 

Our studies of the behavior of plutonium dioxide in molten alkali metal nitrates were conducted in equimolar sodium-potassium nitrate without addition of peroxide. Melt temperatures were low enough so that thermal decomposition was not expected to produce peroxide species. In addition, we studied... 

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