patient zero
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Notes on Sodium Nitrite made by lead oxidation
If you try to make sodium nitrite from sodium nitrate and lead, please replace
the lead with tin. It works exactly the same way. Also SnO2 (white) is the
more stable Tin-oxide,the reaction will give SnO (black)...
The original patent said "use lead or a similar metal"...
I did this reaction often and exothermic runaways are a concern.If this happens
the reaction behaves like burning gunpowder and heavy fumes of metal oxide
evaporates.If this happens with lead and without a fume hood,it renders the
place as unusable...
Beside this and after some practise, the reaction works fine. The key-secret is
to use the right impeller and slow but powerful overhead steering, of this surface
reaction.
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patient zero
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When the reaction is complete, it is a MUST to dump the still hot and creamy mixture
SnO/NaNO2 into water. Otherwise you end up with an unusable rock.
Filter the black sludge and let it dry. Then mix it with an excess of coal by grinding them
together. Burn that mixture,to recover the tin.
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AndersHoveland
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Thanks, this is some good practical information.
I prefer to make sodium nitrite from mixed nitrogen oxides, by passing the gas into basic solution:
2 NaOH + NO2 + NO --> 2 NaNO2 + H2O
The nitrogen oxides can be prepared by reacting nitric acid of a particular concentration with copper. If the nitric acid is too concentrated, all the
gas given off will be nitrogen dioxide. If the nitric acid is more dilute, all the gas given off will be nitric oxide. And if the nitric acid is too
dilute, the reaction will be too slow. It is best to use a moderate concentration, to produce a good mixture of both NO2 and NO, but err on the side
of an excess of NO to avoid the formation of any nitrate in the product. Any excess nitric oxide will not be absorbed.
Sodium carbonate can also be used to absorb the nitrogen oxides. After boiling out the water in a distillation flask, and allowing to cool, the sodium
nitrite crystallizes out in nice big cubic crystals. It is important not to expose the sodium nitrite to air for a prolonged period, as it gradually
oxidizes to nitrate.
Nitrogen dioxide can also be prepared by reacting 50-70% concentrated nitric acid with isopropanol. A portion of the NO2 can then be reduced to nitric
oxide by passing through a solution of ferrous sulfate, FeSO4. You will need holed stoppers and glass tubing, to pass the gases from one reaction
flask to the next. It is very problematic to use ordinary rubber hose, since the moist NO2 can be very corrosive over the course of the reaction.
Likely you will have to use rubber stoppers, which is okay, but just be aware that they will probably be slightly disfigured at the end of the
procedure.
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