Sodium azide chemical reactions

Mechanical treatment alone may be sufficient to induce significant decomposition such processes are termed mechanochemical or tribo-chemical reactions and the topic has been reviewed [385,386]. In some brittle crystalline solids, for example sodium and lead azides [387], fracture can result in some chemical change of the substance. An extreme case of such behaviour is detonation by impact [232,388]. Fox [389] has provided evidence of a fracture initiation mechanism in the explosions of lead and thallium azide crystals, rather than the participation of a liquid or gas phase intermediate. The processes occurring in solids during the action of powerful shock waves have been reviewed by Dremin and Breusov [390]. 

Vehicle air bags protect passengers by allowing a chemical reaction to occur that generates gas rapidly. Such a reaction must be both spontaneous and explosively fast. A common reaction is the decomposition of sodium azide, NaN , to nitrogen gas and sodium metal. 

IXacing cars, such as the one shown helow, can reach speeds that are well above 200 km/h. In contrast, the maximum speed of many farm tractors is only about 25 km/h. Just as some vehicles travel more quickly than others, some chemical reactions occur more quickly than others. For example, compare the two reactions that occur in vehicles the decomposition of sodium azide in an air bag and the rusting of iron in steel. 

When an automobile collision activates an air bag, sodium azide, NaN3(g), decomposes to form sodium, Na(s), and nitrogen gas, N2(g). (The gas inflates the bag.) This chemical reaction occurs almost instantaneously. It inflates the air bag quickly enough to cushion a driver s impact in a collision. 

The workup for such reactions involves neutralization and concomitant generation of salts such as NaCl, Na2S04, and (NH4)2S04. The ehmination of such waste streams and a reduction in the dependence on the use of hazardous chemicals, such as phosgene, dimethyl sulfate, peracids, sodium azide, halogens, and HF, are primary goals in green chemistry. 

Sodium azide is a toxic as well as an explosive substance (Patnaik, P. 1999. A Comprehensive Guide to the Hazardous Properties of Chemical Substances, 2nd e(j New York John Wdey Sons). Although inert to shock, violent decomposition can occur when heated at 275°C. Contact of solid or solution with lead and copper must be avoided. Reactions with halogens, carbon disulfide, or chromyl chloride can be explosive. Dissolution in water produces toxic vapors of hydrazoic acid. The salt is an acute poison causing headache, hypotension, hypothermia, and convulsion. 

As long ago as 1896 Walther [43] observed that as the result of chemical reaction between ethyl nitrate and phenylhydrazine at an elevated temperature, aniline, ammonium nitrate and nitrogen are formed. If the reaction takes place in the presence of sodium ethoxide then, according to Bamberger and Billeter [44] even at room temperature nitrite ions, nitrogen, benzene, phenyl azide, azobenzene, nitrobenzene, aniline, acetic acid and acetaldehyde are formed. 

Sodium azide (Sigma Chemical Company) was used to protect the solution s components from microbial attack during the prolonged reaction period. 

The enthalpy of formation of the azide radical is 467 SkJmoR. The spin-allowed dissociation to N( D) and N2(X 1 +) is endoergic by 225kJmol, the dissociation enthalpy to N( S) - -N2(X i +) is 0.5 IkJmol. The azide radical is only stable because this spin-forbidden decomposition pathway has an appreciable energy barrier. In aqueous solution, it primarily exists as a monomer, in contrast to other halide or pseudohaUde radicals that exist as the less reactive dimers (e. g. Brs (SCN)2 ). Reaction ofthe azide radical with halogen atoms or other small molecules hke O2, NO, CO, and CO2 produces molecules in electronically excited states because of propensity rules, which can be used for chemically pumped lasers. The azide ion is also formed during high-pressure photolysis of sodium azide. 

Generation of peroxynitrite by pulse radiolysis involves very tricky adjustments of concentrations of additives and many other experimental conditions. Radiolysis of aerated aqueous solutions containing sodium formate and potassium nitrite in the pH range 3 to 10 produced peroxynitrite according to Eqs. (21) to (23), (40), (41) and (11). For this, initial concentrations of nitrite and formate have to be adjusted in such a way that the radiolytically produced concentration of the radicals of [0 ] -l- [HOj] > NO. However, reactions of peroxynitrite with antioxidants are not generally studied by pulse radiolysis technique. Chemical methods such as ozonolysis of alkaline sodium azide solutions are commonly used to produce peroxynitrite in large quantities and its reactions studied by mixing techniques. 

The chemical reactions Sodium azide (NaN3) is the chemical that produces nitrogen gas to inflate the air bag. Sodium azide pellets, an igniter, infla-tor, and a tightly folded nylon air bag are stored under a breakaway cover in the steering wheel or dash. The igniter provides a current to decompose the sodium azide into nitrogen gas and sodium. 

COPPER (7440-50-8) Cu The powder forms the friction-, heat-, or shock-sensitive explosive detonator, copper acetylide, with acetylene gas acetylenic compounds and ethylene oxides. The powder forms explosive materials with azides (e.g., sodium azide forms potentially explosive copper azide). Finely divided material forms friction-, heat-, or shock-sensitive explosive with powdered divided bromates, chlorates, and iodates of barimn, calcimn, magnesium, potassium, sodium, or zinc. Violent reaction, possibly explosive, when finely dispersed powder comes in contact with strong oxidizers ammonium nitrate alkynes, bromine vapor, calcium carbide, chlorine, ethylene oxide, hydrazine mononitrate, hydrogen peroxide, hydrogen sulfide, finely divided bromates, iodine, lead azide, potassium peroxide, sodium peroxide (incandescence), sulfuric acid. Incompatible with acids, anhydrous ammonia chemically active metals such as potassium, sodium, magnesium, and zinc, zirconium, strong bases. 

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