Explosion, reaction

Manganese is the third most abundant transition metal, and is widely distributed in the earth s crust. The most important ore is pyrolusite, manganese(IV) oxide. Reduction of this ore by heating with aluminium gives an explosive reaction, and the oxide Mn304 must be used to obtain the metal. The latter is purified by distillation in vacuo just above its melting point (1517 K) the pure metal can also he obtained by electrolysis of aqueous manganese(II) sulphate. 

Chloroform and carbon tetrachloride must not be heated with metallic sodium as an explosive reaction is likely to take place (see footnote, p. 321). 

Manufacture and Economics. Nitrogen tritiuoride can be formed from a wide variety of chemical reactions. Only two processes have been technically and economically feasible for large-scale production the electrolysis of molten ammonium acid fluoride and the direct fluorination of the ammonia in the presence of molten ammonium fluoride. In the electrolytic process, NF is produced at the anode and H2 is produced at the cathode. In a divided cell of 4 kA having nickel anodes, extensive dilution of the gas streams with N2 was used to prevent explosive reactions between NF and H2 (17). 

Halogens, Hydrogen Halides, and Other Covalent Halides. Most compounds containing Si—H bonds react very rapidly with the free halogens. An explosive reaction takes place when chlorine or bromine is allowed to react with SiH at room temperature, presumably forming halogenated silane derivatives (3). At lower temperatures, the reactions are moderated considerably, for example. 

At higher temperatures the presence of alkaU causes an explosive reaction that does not stop at the bimolecular stage. Precautions must therefore be taken to exclude traces of alkaU when handling succinic anhydride. 

Reaction with hydrogen at 220°C in the presence of reduced nickel catalyst results in total decomposition to hydrogen chloride and carbon. An explosive reaction occurs with butylUthium in petroleum ether solution (4). Tetrachloroethylene also reacts explosively with metallic potassium at its melting point, however it does not react with sodium (5). 

Chlorohydfination occurs as the propylene and dissolved chlorine pass up through the tower. It is important that no significant amount of free chlorine remain ia the effluent gas as this could cause explosive reactions. After scmbbiag through a solution of NaOH and a sufficient amount is bled off to prevent accumulation of iaert gases, the effluent gas is mixed with fresh propylene and fed back to the reactor. Fresh water is fed iato the recirculation... 

The nitric acid is added with care to the acetic acid-acetic anhydride solution, keeping the temperature below 20° by means of a bath of ice and salt. An explosive reaction will take place if the nitric acid is added too rapidly. 

Explosive reactions can occur between oxygen and a wide range of chemicals including organic compounds (such as acetone, acetylene, secondary alcohols, hydrocarbons), alkali and alkaline earth metals, ammonia, biological specimens previously anaesthetized with ether, hydrogen and foam rubber. 

Materials which (in themselves) are readily capable of detonation or of explosive decomposition or explosive reaction at normal temperatures and pressures. Includes materials which are sensitive to mechanical or loceilized thermal shock. If a chemical with this hazard rating is in an advanced or massive fire, the area should be evacuated. 

The process is subject to explosive reaction or detonation under nonnal conditions... 

The violence of an explosion is influenced by the initial pressure or pressure of the system in which the explosion takes place. Figure 7-57 illustrates this point for propane and a constant ignition energy source. For low pressure below aunospheric, the explosion reactions are reduced until they will not propagate through the fuel-air mixture [54]. 

It is not advantageous to work with larger quantities as an explosive reaction is liable to occur if stirring is stopped. 

Like nitrocellulose, nitroglycerin also undergoes a slow first-order exothermic decomposition at temperatures below 140°C. As the pressure is increased, this decomposition reaction is followed by a sudden explosive reaction. Evidence suggests that the explosive reaction is autocatalyzed by the accumulation of N02. The combined results of several studies indicate that... 

Reaction involves more than a single step. The relative thermal stabilities of the hexammine salts, as determined by the temperatures of onset of the reaction, are Cl" > Br for the cobalt compounds but Br" > Cl" > I" for the chromium compounds. When X = NOi, rapid oxidation developed into an exothermic explosive reaction of both the Cr and the Co salts. 

Some reactions, such as the explosive reaction of hydrogen and oxygen, appear to proceed to completion, but others seem to stop at an early stage. For example, consider the reaction that took place when Haber heated nitrogen and hydrogen under pressure in the presence of a small amount of the metal osmium ... 

Materials or substances, which can, by themselves, detonate or cause an explosive reaction, but need a source that initiates these decompositions or reactions or need to be heated in containment. This includes substances that are sensitive to mechanical or thermal shocks at high temperature and/or pressure or that react explosively to water. 

As an example a violent reaction that brings together, in an industrial process, two substances responsible for explosive reactions will be discussed because it is no longer in use ie. ... 

When there are reducing agents present, sodium perborate gives an explosive reaction, it is less dangerous if the perborate is hydrated. 

Sodium and potassium nitrates give an explosive reaction with lithium. 

Thus, all copper salts give an explosive reaction with calcium carbide. This is due to the formation of explosive copper acetylide, which is formed from cupric or cuprous cation and the acetylene formed. 

Zinc gives an explosive reaction with manganese dichloride, whereas with calcium chloride, which was in a galvanised iron container, the detonation is blamed on the overpressure created by the release of hydrogen, which is formed in these conditions. 

Bromine creates an explosive reaction with ozone at ambient temperature and pressure. 

It creates violent or even explosive reactions when it is mixed with melted ammonium nitrate. 

Tin chlorides have the same dangerous reactions as the chloride ion and, as far as tin (ll) derivatives are concerned, as oxidation reactions. Therefore, potassium gives the usual explosive reaction with both chlorides. 

All other dangerous reactions consist of oxidations of bismuth by strong oxidants. Thus, chloric and perchloric acids lead to highly sensitive explosives (probably bismuth chlorate and perchlorate). Fuming nitric acid causes the incandescence of bismuth at ambient temperature whereas a detonation occurs when molten bismuth is mixed with concentrated nitric acid. Rnally, a bismuth/molten ammonium nitrate mixture causes a very violent or even an explosive reaction. 

Organoaluminium derivatives with the formuia RxAIZ3 x (Z = OR, OH, X) give rise to explosive reactions with methanol and ethanol. With very strong bases, the reaction can be written down as ... 

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