Sodium hyponitrite

In contrast to the stepwise oxidation of sodium hyponitrite in liquid N2O4, the oxidation goes rapidly to the nitrate ion in an inert solvent of high dielectric constant such as nitromethane ... 

Sodium progressively reduces the nitrate, eventually forming a yellow explosive solid, probably sodium hyponitrite. 

Many of the following powdered metals reacted violently or explosively with fused ammonium nitrate below 200°C aluminium, antimony, bismuth, cadmium, chromium, cobalt, copper, iron, lead, magnesium, manganese, nickel, tin, zinc also brass and stainless steel. Mixtures with aluminium powder are used as the commercial explosive Ammonal. Sodium reacts to form the yellow explosive compound sodium hyponitrite, and presence of potassium sensitises the nitrate to shock [1], Shock-sensitivity of mixtures of ammonium nitrate and powdered metals decreases in the order titanium, tin, aluminium, magnesium, zinc, lead, iron, antimony, copper [2], Contact between molten aluminium and the salt is violently explosive, apparently there is a considerable risk of this happening in scrap remelting [3],... 

A procedure for preparation of sodium hyponitrite involving reduction of nitrogen oxide by the ketyl, followed by extraction into water [1], had been operated routinely on the small scale. A 41-fold scaled up run exploded and ignited after 200 ml of water had been added as part of the work-up. This was attributed to the presence of an unusually large proportion of coagulated unreacted sodium in the ketyl. Small-scale operation with precautions is urged [2],... 

Sodium hypnnitrite Na N 0 is formed (I) by reaction of sodium nitrate or nitrite solution with sodium amalgam (sodium dissolved in incrcuryl, alter which acetic acid is added to neutralize the alkali. Sodium stannite ferrous hydroxide, or electrolytic reduction w ith mercury cathode may also be utilized. (2) by reaclion of hydroxylamine sulfonic acid and sodium hydroxide. Silver hyponitrite is formed by reaclion of silver nitrate solution and sodium hyponitrite. 

The reduction of nitrates, nitrites, or nitric oxide.—In 1871, E. Divers found that when a soln. of sodium nitrite or nitrate is treated with sodium amalgam, the nitrite or nitrate is reduced to sodium hyponitrite 2NaN03+[8H]... 

H20- -Na2N202. The soln. should then be treated with yellow mercuric oxide to destroy the hydroXylamine, and filtered. The alkaline liquid is neutralized by acetic acid, and, when silver nitrate is added, a precipitate of silver hyponitrite, Ag2N202, is formed. E. Divers prepared sodium hyponitrite by the following process ... 

E. Divers prepared the basic salt cupric hydroxy hyponitrite, Cu2(0H)2N202, according to A. Thum. This salt was also made by S. S. Kolotoff, A. Thum, and A. Kirsehner. It is obtained by adding sodium hyponitrite to a soln. of a cupric salt. The acid liquor so obtained deposits more salt when neutralized. A small quantity of this salt is precipitated when an excess of cupric sulphate is added to a soln. of hydroxylamine sulphate, and then a little ammonia. The sea-green salt is very stable it gives water, a mixture of cupric and cuprous oxides, and nitric and nitrous oxides when heated. The salt can be boiled with water without losing its colour, but it is decomposed by a soln. of sodium hydroxide. It is soluble in dil, acids and aq. ammonia. E, Divers tried unsuccessfully to make cuprous... 

According to E. Divers, normal mercuric hyponitrite, HgNa02, is obtained by precipitation from sodium hyponitrite and mercuric nitrate. The mixed soln. of sodium hydroxide and hyponitrite obtained by reducing sodium nitrite with sodium amalgam is diluted and almost neutralized by dil. nitric acid keeping the soln. ice-cold all the time. It is then poured into a soln. of mercuric nitrate which must not be in excess, and should contain as little free acid as possible. The slightly turbid mother-liquor is decanted from the precipitate, and, after being neutralized... 

A. E. Menke found aluminium hyponitrite is formed as a white precipitate when sodium hyponitrite is added to a soln. of an aluminium salt. It is insoluble in water, and in acetic acid. The precipitate of cerium hyponitrite obtained in an analogous way is soluble in acetic acid likewise also tin hyponitrite, which is insoluble in acetic acid and lead hyponitrite. E. Divers, A. Thum, and A. Kirsehner prepared lead hyponitrite, PbN202, by the action of a soln. of sodium hyponitrite on a lead salt. The precipitate at first is cream coloured and flocculent, but it soon becomes sulphur-yellow, and the dense, cream-coloured salt is probably a hydrate A. Kirsehner, said E. Divers, mistook it for a basic salt... 

A. E. Menke prepared bismuth hyponitrite as a white precipitate by adding sodium hyponitrite to a soln. of a bismuth salt. It is insoluble in acetic acid. The analogous precipitates of white manganese hyponitrite, red cobalt hyponitrite, and of green nickel hyponitrite are soluble in acetic acid. With ferrous salts, olive-green ferrous hyponitrite is formed, it is insoluble in water, and becomes yellow when treated with acetic acid. With ferric salts, yellow ferric hyponitrite is formed—insoluble in water, soluble in acetic acid. With potassium salts, platinum hyponitrite is formed which is less soluble in acetic acid than it is in water. 

Sodium hyponitrite, Na2N202.—The hyponitrite can be prepared by reducing sodium nitrite with sodium-amalgam5 and precipitating the solid by addition of alcohol to the solution. The reduction can also be effected by means of sulphur dioxide.6... 

Sodium hyponitrite is readily soluble in water, the concentrated solution being stable in presence of a large proportion of sodium hydroxide. On crystallization the salt is deposited as pentahydrate, this substance losing its water of crystallization in a desiccator or on exposure to air. The anhydrous salt is the more stable form it melts with decomposition at 300° C. The cryoscopic method gives the double molecular formula, Na2N202. 

Hyponitrous acid, HgNgOg, has been made from its salts. A solution of sodium hyponitrite is produced by reducing concentrated aqueous NaNOg with sodium amalgam. The insoluble silver salt, precipitated from neutral solution, when treated with anhydrous HCl in dry ether gives the acid ... 

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