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Alkoholvergiftung
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It was from 1864.So the lag of knowlege.
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woelen
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This kind of old information can be really interesting. I believe that in old books and papers there is a lot of interesting information about common
compounds, which is totally forgotten nowadays. This is exactly, why I love to read old books from around 1900 or so.
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unionised
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Quote: Originally posted by Lionel Spanner  | | Quote: Originally posted by unionised |
Am I reading this correctly? The yield is about 50 micro moles per square cm per week.
So, with a 10cm by 10 cm electrode you would get less than a quarter of a gram of nitrite per week.
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That's with 0.1 molar ammonia, i.e. 0.17% w/v. I suspect a more concentrated solution would result in better yields.
[Edited on 22-8-2023 by Lionel Spanner] |
I suspect that a higher NH3 concentration would increase the yield of N2 at the expense of NO2- ions.
And the reasons for my suspicion are the law of mass action and the instability of ammonium nitrite.
But, until someone does the experiment, we won't know.
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unionised
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This tells you more than you probably want to know about decomposing copper acetate.
https://www.scirp.org/journal/paperinformation.aspx?paperid=...
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Fantasma4500
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Major success- breakthrough
| Quote: Originally posted by woelen |
Very finely divided metallic copper is first prepared by distillation of acetate of copper, and from this freshly prepared metallic powder, 2
equivalents, or even a slight excess, are taken to 1 equivalent of saltpeter, according to the equation
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you think thats an interesting quote? this is a marvellous breakthrough in nitrite preparation. i just tried it, mixed 3.2g KNO3 with 3.2g copper
sponge i made from copper-copper electrolysis, NaCl + .. 1-3% HCl?
i believe CuCl2 + Al would also give copper fine enough for this
i folded up some aluminium foil and heated the mixture with a blowtorch until it melted and torched the top as well, maybe 5 seconds, it glowed from
the flame
dipped that into 10mL water and shook it until the solid came off, black solid
it dissolved effectively, good sign. a few mL IPAlcohol in, a squirt of 10% H2SO4 and both vasodilatory + flame test proved success, i only took maybe
100mg sample to torch
no need for copper acetate decomposition, electrolytic copper sponge is plenty fine
a chemist proposed that Cu2O may also work, but that only makes sense if we can make Cu2O very easily.. CuCl2 + Al goes quite fast especially if you
can dump in a bunch of ice as well to keep it under control
this reaction should go very well with a hotplate and pot ontop, metal crucible, insulated with aluminium wool
edit: NaNO3 works too
[Edited on 28-8-2023 by Fantasma4500]
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Alkoholvergiftung
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FeO very fine should work too.
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Fantasma4500
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FeO is made from iron oxalate, i already tried NaNO3 + iron oxalate heated together, poor results
copper powder works. its solved.
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Fantasma4500
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reporting grand success with electrolytic copper and NaNO3, 120g + 120g copper, heated together at about 400*C for an hour in closed container, black
lowdensity crumbling spongy material achieved
120g NaNO3 used, 100g in 400mL H2O acquired, theoretically 120g NaNO3 turns into 97g NaNO2
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Alkoholvergiftung
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to bad if it was closed maybe it reacts like stated at 200-250C exotherm. Would much easier to reach with an hotplate.
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Fantasma4500
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reporting in that Cu2O also works quite well, may even work better than copper metal
CuO is widely available, Cu2O was made by reacting solution of ascorbic acid with heating with CuO which i acquired from previous Cu + NaNO3 run,
looking for alternatives to ascorbic acid as HCl + CuO + Al is also very easy, and aluminium in that case is the reducing agent
CuO and Cu2O is roughly same price, onyxmet lists Cu2O as 4.00 euros where CuO is 3.75 euro for 10 grammes
1188g KNO3 + 1681g Cu2O = 1000g KNO2 + 1869g CuO
CuO seems possible to reduce with sugar and some salt like sodium citrate and copper sulfate, maybe glucose and sodium hydroxide?
[Edited on 2-9-2023 by Fantasma4500]
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Rainwater
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| Quote: Originally posted by Fantasma4500 | reporting grand success with electrolytic copper and NaNO3, 120g + 120g copper, heated together at about 400*C for an hour in closed container, black
lowdensity crumbling spongy material achieved
120g NaNO3 used, 100g in 400mL H2O acquired, theoretically 120g NaNO3 turns into 97g NaNO2
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How was the product isolated for yield measurement?
"You can't do that" - challenge accepted
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Fantasma4500
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| Quote: Originally posted by Rainwater | | Quote: Originally posted by Fantasma4500 | reporting grand success with electrolytic copper and NaNO3, 120g + 120g copper, heated together at about 400*C for an hour in closed container, black
lowdensity crumbling spongy material achieved
120g NaNO3 used, 100g in 400mL H2O acquired, theoretically 120g NaNO3 turns into 97g NaNO2
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How was the product isolated for yield measurement? |
well its a very clean reaction and zero nitrate is claimed by wolens reference, barely any "gunpowder" smell detectable inside the reaction vessel
after a whole hour of operating, seeing that after i heated a 10mL solution sample in oven for an hour with fan going, and there was still aggressive
amounts of nitrite in it, i wager that i have a solution is quite pure sodium nitrite, i could maybe get a bit extra scientific with using silver
nitrate to precipitate it out but im okay with just believing its pure enough for my desires. its a very easy reaction so i invite anyone else more
eager for data to repeat it, also for the sake of science and replication
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Lionel Spanner
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Below is a useful quantitative assay I've used in the past for testing the purity of nitrite.
1. Weigh accurately about 1.0 g of the sample of sodium or potassium nitrite to be assayed into a 250 mL volumetric flask, and record the weight (W).
2. Fill the flask about halfway with deionised water, and mix until all solids are dissolved.
3. Once all solids are dissolved, make up to the mark with deionised water.
4. Weigh 5% sulphuric acid (75 g) into a 250 mL conical flask.
5. Add 0.02M (0.1N) potassium permanganate solution (25 mL) to the conical flask via a pipette.
6. Titrate the contents of the flask with the nitrite solution. The end point is reached when the mixture just goes colourless; record the volume of
solution delivered (T).
7. The % purity of the assayed sample can be determined by the following equation:
%P = 2156.25 ÷ T ÷ W (for sodium nitrite)
%P = 2626.25 ÷ T ÷ W (for potassium nitrite)
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Fantasma4500
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just wanted to add CuO as from the reduction reaction can be reduced to Cu2O using glucose and NaOH, boiled for a few hours
the Cu2O reacts with HCl to form a water soluble salt which is black, upon dilution it becomes CuCl, this is the washed and dried Cu2O so no reducing
agents leftover in it, cool little bonus.
100g NaNO3 needs 160ish Cu2O, NaOH or H2SO4 may be used to turn sucrose into glucose with heating in solution, straight up glucose seemed to work
better tho, ascorbic acid works very well but not as OTC.
KNO3 seems dreadful for making nitrite for some reason, mostly didnt react with some of the copper powder i used, NaNO3 seems much better- probably
because its just a bit more reactive
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Kevlar
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I've read this 21 year long thread and deduced one thing, that by far the best method I have seen is a displcement method -
(Ca(NO3)2) + (Na2SO4), The balanced equation is:
Ca(NO3)2 + Na2SO4 → CaSO4 + 2NaNO3
The stoichiometry of the reaction is a nice 1:1 ratio in moles, both of the chemicals are OTC and cheap & the end clean product being pure 2NaNO3.
Which is easy to sep from the insoluable CaSO4.
I will buy some of both and come back with pictures, I have got a ref sample of the 2NaNO3 to compare with.
I have been saving up a lot of eggshells and might make the Ca(Na3)2 along with the nitric acid from KaO3 + NaCl reaction.
“If you do not expect the unexpected, you will not find it, for it is not to be reached by search or trail.”
(Heraclitus)
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fx-991ex
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We trying to make nitrite NO2 not nitrate NO3.
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Kevlar
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fx-991ex I will make the NaO2 from oxidation of the NaO3 using starch, I just got carried away with doing some inorganic chem.
But thanks for pointing that out to me!
“If you do not expect the unexpected, you will not find it, for it is not to be reached by search or trail.”
(Heraclitus)
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RU_KLO
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Im trying to make NaNO2 for first time.
I choose NO2+NO bubbling in NaOH.
So I made a 4M NaOH solution (100 ml), in which a mix of NO2 - NO gas was bubbled.
NO2-NO gas was made from copper + 7M (aprox) HNO3 dripping (100ml). The dripping was adjusted, as so the inner color of the reaction flask. Mild -
almost transparent - red brown color was tried. (i.e. one drop every 1-2 seconds).
All this was in a negative pressure setup (a cheap 12V water/air pump was used).
It took a while - maybe 2 hours and copper needed to be replenished.
After this, ph was meassured, it was highly alkaline (NaOH excess).
(on a test, after adding some acid to a sample, till acidic, there were some red fumes from this solution. So probably some NaNO2 was in solution)
Next HNO3 was added to neutralize the NaOH. Ph was taken to 6-7.
Next a solution of Na2SO3 (unknown molarity) was added.
The idea was to transform the NaNO3 (from the neutralization) to NaNO2.
(some sulfur was in the Na2SO3 and some sulfur was precipitated - or I think it was
At the end was left with 250 ml which was boilled down till 50-40ml which crashed "a lot" of salt. (check picture)
Now, I need to somehow purify and get NaNO2.
Whats in the "soup":
1) 2 NaOH + NO2 + NO → 2 NaNO2 + H2O
2) NaOH + HNO3 = NaNO3 + H2O
3) Na2SO3 + NaNO3 = NaNO2 + Na2SO4 (maybe?) is this correct? (or maybe some sulfur is made?
what are my best route?
1) add more Na2SO3 to convert any NaNO3 left. (will an excess of Na2SO3 hurt?
regarding purification by recristallization, what the best route, because Im not having good results - maybe bad procedure.
NaNO2
Solubility in water
71.4 g/100 mL (0 °C)
84.8 g/100 mL (25 °C)
160 g/100 mL (100 °C)
Na2SO4
Solubility in water
Heptahydrate:
19.5 g/100 ml (0 °C)
44 g/100 ml (20 °C)
Na2SO3
Solubility in water
27.0 g/100 mL water (20 °C).
If I add little water, heat to dissolve everything, and let it crash out, will get the same result.
So how is it done?
a) add boiling water instead of cold till everything dissolves?
b) add cold water till everything is dissolves, remove X% of it (lets say 30%) take it to freezer or ice (0ºC) filter. then remove the last portion
till some cristals are seen?
c) filter what you got, dry, weight and from there, add enough ice cold water to dissolve the NaNO2 but not to the Na2SO4
Example: 10grs (dry mixed salt) was obtained,
(solubility per ml NaNO2 = 0.71gr (0ºC); Na2SO4 (0.195gr (0ºC))
So for NaNO2 is 14 ml of water. and for Na2SO4 is 51.28ml.
So if I add 14ml of H2O 0ºC, NaNO2 will be dissolved and excess of Na2SO4 will not.
Or maybe is simplier o more complicated than this (because of common ion effect)
Any help or step by step procedure for purifying is well received.
As side note, a small sample of this salt was tested with HCl and a lot of red fumes were watched.
and as bonus: If you have Sulfite and nitrate, you could directly made nitrite.... Is this correct?
thanks
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fx-991ex
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I dont think mixing Na2SO3 and NaNO3 in sln will reduce to SO4 and NO2. This usually is done in a crucible under high temp(300C) using CaSO3 instead
of the Na salt.(for ease of purification)
When you add acid it do make red fumes but that do not mean its NaNO2.
The Na2SO3 react with acid to liberate SO2 gas which probably react with NaNO3 to release NO2 while making Na2SO4.
I did something similar last year, mixing NaNO3 and CaSO3 gave red fumes upon addition of Acid. but after removing by filtration the CaSO3(No CaSO4 as
expected), it was only unreacted NaNO3, no red fume upon addition of acid.
What you want to do is, react your Na2SO3 With CaCl2, filter and keep he solid CaSO3. then react this CaSO3 with your NaNO3 under high
temperature(300C for 15 minute).
Then you can filter out the CaSO4 and evaporate water to keep the NaNO2.
Also the CaSO3 crystalize as hydrates so more is needed if its not dehydrated and having a slight excess dont hurt things. Most people seem to
overlook this part giving bad yield because they dont use enough CaSO3.
[Edited on 27-5-2024 by fx-991ex]
[Edited on 27-5-2024 by fx-991ex]
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RU_KLO
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After "bad" news from fx... and that is possible that I do not have any nitrite, performed the following test.
diferent reagents (used in the procedure) where added to a potassium permangante solution to see if they reduce it.
the nitrite? (prepared solution) and the sodium sulfite reduced it, the rest did not. (check picture)
So as fx said, probably I got no nitrite and the excess sulfite is doing the reduction.
So I will try to take a sample of the nitrite? and add some BaCl2 to precipitate BaSO3 (solubility 0.0011 g/100 mL) This will remove the sulfite and
left with nitrite "only" in the solution and check if this new solution reduce the KMnO4.
(note: already tried BaCl2 + Na2SO3 and a fine white precipitate precipitates)
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RU_KLO
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Last experiment was failure.
So i tried the Pb - Nitrate procedure. It seems it worked.
Tested the supernatant, few drops on potassium permanganate in H2SO4, it cleared, so there must be some nitrites.
Currently the Nitrite is drying. Im following Nurd rage permanganate standarization (with Sodium oxalate), so I can follow (previuos in this post)
titration of the nitrite/nitrate, so to know how good it was.
attached some pictures.
The sodium nitrite I got is white, not yellow as stated in this post from others.
The PbO I got is creamy white , but pictures show it is yellow...
Are this colors I got correct?
Lead was from UPS batteries, maybe some contaminats are there.
 
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Rainwater
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PbO is usually black, red, brown or yellow depending on the oxidation state.
That looks like white lead.... googling 2PbCO3·Pb(OH)2wiki
, heating a sample over a flame it should cause a color change, or react it with an acid to evolve CO2.
Heat it to about 650c and it should turn black if its PbO. Just remember its toxic and will contaminate all your gear
"You can't do that" - challenge accepted
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Master Triangle
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The aluminium reduction of potassium nitrate absolutely works to some extent, I dried a sample and the unpurified salt fumes strongly with HCl.
I used 20g KNO3 in 100ml water, with 4g of Al grinding dust, 6060 extrusion alloy, unwashed so it still had a tiny wax contamination and years old so
it is fully oxidised. Stirred and heated on a 55C hotplate. Added a knifetip of Cu2O as a supposed catalyst (no idea if this works in alkaline
conditions, or without chloride). A few drops of isopropyl were used to get floaters to be wetted. NO3- to Al ratio is just above stoichiometric if we
forget about all the reactions we don't want to happen.
Added ammonia and small amounts of NaOH (to dissolve oxide) with minor effect for several hours until it suddenly took off and started boiling from
the very exothermic reaction (this might be a bad idea with Al dust). Continued bubbling for about an hour. It didn't produce nasty amounts of
ammonia, so not sure how much of what came off was added by me and how much was from the reaction.
Ended up with a white precipitate with a few Al particles remaining, filtered that away and dried a sample which filled a vial with NO2 from a drop of
HCl. Just evaporating the rest down now, hopefully the aluminate is mostly precipitated before nitrite+nitrate begins coming out.
Anyone got ideas for removing aluminate, aluminium hydroxide and any excess potassium hydroxide? Not sure about this system, I added the remaining
dried sample back in for the evaporation and it seems there was a fair bit of Al(OH)3 since some would not re-dissolve on heating. The solubility of
nitrite in methanol might do it, and might even help separate some nitrate.
Also, the solution was totally clear and has only taken on the typical yellowish tint as I evaporate it. Is nitrite coloured at all? Or does it just
get the yellow tint from oxidation?
For repetition, there are a few things unclear that could be important: the potassium cation, whether Cu2O does anything, the alloy used. The speed of
the reaction could be important, but a rapid reaction certainly did not destroy all NO2- and probably formed most of it judging by the amount of Al at
that stage.
I'll do a permanganate titration at the end, pretty sure aluminate can't interfere?
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Master Triangle
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Yup, a pretty good success!
From 20g of starting nitrate I crystallised out 8g of unreacted nitrate and titrated what was left against permanganate, getting 5.78g or a yield of
~29%. If you go by just the nitrate that was reacted that would be a nearly 50% yield, or even higher if there was a significant amount that I did not
crystallise (likely).
I believe ammonia could interfere with the titration but that would have all boiled off during evaporation.
I think I'll try to do some optimisation runs, I could have certainly used more aluminium, and there are a lot of other variables to sort out too.
A lot to sort out with purification too; if you are all good with having some nitrate contamination it might be a good idea to add nitric acid to turn
all the KOH into KNO3 which is easy to crystallise out and won't attack your glassware, would probably help with precipitating out Al(OH)3 too. That
would have to be done after boiling off the ammonia to ensure you don't make ammonium nitrate.
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jackchem2001
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I have attempted reduction of KNO3 with CaSO3 a couple of times. I will leave some observations here:
You can't qualitatively monitor the reaction progress by taking samples at various points in time and adding sulfuric acid to them (the intent
being to look for the extent of nitrogen dioxide evolution from any nitrite present). However, the initial reaction mixture gives NO2 on addition of
sulfuric acid - clearly nitric acid generated in-situ is reduced by sulfite, so this method is no good.
The wiki claims heating sodium nitrite to decomposition (300°C - note a much lower temperature than the potassium salt) leaves behind sodium
hydroxide (?) and sodium oxide. In the case of the potassium salt, after leaving the reaction mixture in an open glass dish in an oven at 210-250°C
(using an IR themometer) for perhaps 4 hours, when water was added to the cooled reaction mixture some bubbling was seen. I expected this bubbling to
be from potassium oxide reacting with water to give hydrogen and potassium hydroxide, but the pH was only very slightly alkaline (i.e. the pH of my
tap water).
This suggests to me there may be no disadvantage to leaving the potassium reaction mixture at this temperature range for very long periods of time. If
reaction with atmospheric oxygen is feared, then an open container could be using during the initial heating period which could later be closed once
the system was up to temperature. I think a glass dish inside of a cast iron pot could be used to accomplish this.
My earlier run of this reaction failed - I suspect due to insufficient heating. I am yet to work up my current run.
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