Sodium+Nitrite


 * Sodium nitrite ** is the [|inorganic compound] with the [|chemical formula] [|Na] [|NO2] . It is a white to slight yellowish crystalline powder that is very soluble in [|water] and is [|hygroscopic] . It is a useful precursor to a variety of organic compounds, such as pharmaceuticals, dyes, and pesticides, but it is probably best known as a food additive to prevent [|botulism].

The salt is prepared by treating sodium hydroxide with mixtures of [|nitrogen dioxide] and [|nitric oxide] :

2 NaOH + NO2 + NO → 2 NaNO2 + H2O The conversion is sensitive to the presence of oxygen, which can lead to varying amounts of [|sodium nitrate].

In former times, sodium nitrite was prepared by reduction of sodium nitrate with various metals In the laboratory, sodium nitrite can be used to destroy excess [|sodium azide]. 2 NaN3 + 2 Na NO2 + 2 H+ → 3 N2 + 2 NO + 2 Na+ + 2 H2O At high [|temperatures], sodium nitrite decomposes [|sodium oxide] , [|nitrogen(II) oxide] and [|oxygen].

Industrial chemistry
The main use of sodium nitrite is for the industrial production of organonitrogen compounds. It is a reagent for conversion of [|amines] into [|diazo] compounds, which are key precursors to many dyes, such as [|diazo dyes]. [|Nitroso compounds] are produced from nitrites. These are used in the rubber industry.

Other applications include uses in [|photography]. It may also be used as an [|electrolyte] in [|electrochemical grinding] manufacturing processes, typically diluted to about 10% concentration in water. It is used in a variety of metallurgical applications, for phosphatizing and detinning.

Medicine
Sodium nitrite can be used as part of an intravenous mixture to treat [|cyanide poisoning]. However it has now been made obsolete by [|hydroxocobalamin] if this newer medicine is available.

There is also research to investigate its applicability towards treatments for [|heart attacks], [|brain aneurysms] , [|pulmonary hypertension] in infants, and [|Pseudomonas aeruginosa] infections.

Food additive
In the early 1900s, irregular [|curing] was commonplace, this led to further research surrounding the use of sodium nitrite as an [|additive] in [|food], standardizing the amount present in foods to minimize the amount needed while maximizing its [|food additive] role.Through this research, sodium nitrite has been found to inhibit growth of disease causing [|microorganisms] ; give taste and color to the meat; and inhibit lipid oxidation that leads to rancidity The ability of sodium nitrite to address the above mentioned issues has led to production of [|meat] with improved [|food safety] , extended storage life and improving desirable color/taste.In the European Union it may be used only as a mixture with salt containing at most 0.6% sodium nitrite. It has the [|E number] E250. [|Potassium nitrite] (E249) is used in the same way. It is approved for usage in the EU, USA and Australia and New Zealand.