Metals combustion, in air

AlkaU metals react with oxygen to form oxides, peroxides, and superoxides, depending on the metal. Combustion in air yields the following products ... 

Chemical Features of Metals Combustion in Air (Experimental Background) 131... 

There are little data available. The only piece of information consists in rhodium being obtained by the reduction of its derivatives by hydrogen. The metal obtained occludes large quantities of hydrogen. If it is desorbed from hot rhodium, it combusts in air. Thus, the treatment has to be carried out in inert gas. Rhodium is inert, not even fluorine reacts with it. It occludes oxygen, but only reacts slowly when it is hot. It reacts with halogens at very high temperatures. 

Combustion in air or oxygen produces lanthanum sesquioxide. However, at ambient temperatures, when exposed to moist air, the metal forms a hydrated oxide with a large volume increase. 

Another common source of spontaneous combustion is by oxidation, especially oxidation of finely divided metals or metallic powders or certain fats and oils. Metal powders which have been produced in inert atmospheres are especially susceptible to spontaneous combustion in air because their unoxidized surfaces are highly reactive. 

For solvents in which the lifetime of the solvated electron is short, it cannot be observed in this way. For instance in water, the hydrated electron may be formed by dissolving alkali metals. But the metal dissolution timescale is much longer (a hundred of milliseconds) than the lifetime of the electron (a few microseconds) and, as soon as solvated electrons are produced, a very fast reaction occurs between two solvated electrons producing molecular hydrogen, leading to the explosive combustion in air that accounts for the hazardous contact of alkali metal and water. 

Beryllium Methyl, Be(CHs)s Beryllium Ethyl, BeCCoHj), Beryllium Propyl, BeCCaH,),.—Beryllium ethyl was first prepared by Cahours (i860 i) by the action of metallic beryllium on ethyl iodide in a sealed tube. In later experiments, (1873 i), he produced enough to study by the action of beryllium on mercury ethyl. Found it to be a colorless liquid boiling at 185°-188°. It is spontaneously combustible in air and is decomposed by water. It can be distilled in an atmosphere of carbon dioxide. Beryllium propyl was also prepared by Cahours (1873 i)... 

Nitrides (Oxynitrides) Formation by Metal Powder Combustion in Air 133... 

The oxidation of A1 powders with rare-earth metals added to embrittle the oxide shell on A1 particles was studied in [28-30]. The introduction of such additives reduces the agglomeration of particles during combustion, and increases combustion efficiency and flame temperature. The use of nMe additives to nAl is one of the factors affecting the yield of nitride phase in the CCP. The highest yield of AlN (up to 66 mass%) in CCP at nAl combustion in air was observed for the additives nFe, nMo, and nW. 

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