trinitrotoluene - 11-1-2003 at 16:45
Well after 4 months of wanting to get HNO3 I was tired of waiting so I had decided to make my own without proper equipment.So In a 250ml flask I
poured 91ml of 93% H2SO4 into there. Then I added 150 grams of powdered NaNO3 while stirring. After its dont the mixture is unstirrable. Then I got
some plastic tubing called Vinyl Its clear and flexable and I obtained it from the local Hospital. And I don't have rubber stoppers so I just made Al
foil into a ball and inserted the tubing. I then connected the tubeing to the 250ml flask , thats the one with the HNO3 I want to distill. Then I did
the same to the other flash whick is a 125ml red flask and I put it in a ice bath. Thats the flask used to condense the HNO3. The final thing I did
was Seal it with masking tape so the NO2 and HNO3 vapor won't escape. I had decided to do the experiment outside. After a few minutes when the HNO3
stated boiling I can see that the plastic tubing is getting attacked by the acid. But I ignoured it and keep distilling. After that the plastic tubing
near the 250ml flask started to melt the boil. After a few seconds it bust into A tower of flames. And a huge tower of black smoke was formed it
smelled like NO2 and burning plastic. After the fire died down I poured water to put it out. I then cleaned up and I managed to get 10ml of orange
HNO3 distilled.But that was scary what had happend.
vulture - 11-1-2003 at 17:02
Vinyl tubing = polyvinylchloride.
Strong oxidizing agents will replace chlorine with oxygen (because of the higher electronegativity) and often attack the carbon skeleton.
HNO3 is already a powerful oxidizer and as a hot gas it is ofcourse much more reactive.
rikkitikkitavi - 11-1-2003 at 23:57
and you used way to much KNO3. Atleast a molar ration of 2:1 is good, so the mixture becomes more liquid.
KNO3+ H2SO4 => KHSO4 + HNO3.
At the temperatures involved KHSO4 is preferably a solid, since otherwise HNO3 will decompose. Excess H2SO4 will make the mixture more liquid,
increasing heat transfer and preventing local overheating in the flask where the heat is applied.
Hot NO2 is a vile compound! Ask the russians who had several rockets go up at launch bay...
Only tubing you can use is PTFE. Should be available in well sorted hardwarestores och companies selling electrical cables and tubing for these.
And forget about the rubber corks..
/rickard
Alienrocketscientist - 4-9-2017 at 08:06
There is one other plastic which can withstand hot HNO3 and NOx under pressure. I distill anhydrous HNO3 using pressure instead of a vacuum. Why?
Because the pressure effects both the vapor point and decay of the HNO3 as the reaction is driven at temps up to 420°F. Kept under significant
pressure there is little tendency to decay, and also a different byproduct, gaining TWICE the HNO3 normally produced using conventional methods. The
end product is solid at 420°F. After each use the heating vessel is reusable after stream of hot water dissolves the solid byproduct.
Basically it os HNO3 synthesis as it would be done on a planet with different atmospheric conditions.
On a side note, if H2O were used to dissolve the nitrate, the pressure also effects the vapor pressure of HNO3 differently than the vapor pressure of
the water, allowing a higher aziotrop, this higher concentration of nitric acid solution.
The whole process has more potential problems, but after knowing what to watch for in driving the reaction, these problems don't ever manifest
themselves to the degree the OP has experienced.
Specific gravity of end product is always 1.52 - 1.51, which works for me.
Alienrocketscientist - 4-9-2017 at 08:48
There is one other plastic which can withstand hot HNO3 and NOx under pressure. I distill anhydrous HNO3 using pressure instead of a vacuum. Why?
Because the pressure effects both the vapor point and decay of the HNO3 as the reaction is driven at temps up to 420°F. Kept under significant
pressure there is little tendency to decay, and also a different byproduct, gaining TWICE the HNO3 normally produced using conventional methods. The
end byproduct is solid at 420°F. After each use the heating vessel is reusable after stream of hot water dissolves the solid byproduct.
Condensation occurs in two stages, the first to condense and preserve the anhydrous HNO3, and the fourth to capture the byproducts of the first
stage, where carbon is introduced and two other byproducts are recovered. The first to be recovered is HNO4 in a liquid form which combined with the
introduced carbon goes through an uptake phase depositing itself on complex crystaline ice structures. The end bypructs are able to be isolated, both
being very high energy, one which by far surpasses CL-20 in it's energy outputand it's density.
Basically it is HNO3 synthesis as it would be done on a planet with different atmospheric conditions.
On a side note, if H2O were used to dissolve the nitrate, the pressure also effects the vapor pressure of HNO3 differently than the vapor pressure of
the water, allowing a higher aziotrop, this higher concentration of nitric acid in the solution.
The whole process has more potential hazards and problems, but after knowing what to watch for in driving the reaction, these problems don't ever
manifest themselves to the degree the OP has experienced.
Specific gravity of end product is always 1.515 - 1.525which works for me (I use the mean between the two... as my method to determine specific
gravity is by using the weight, not mass, of the volumetric samples.)
[Edited on 4-9-2017 by Alienrocketscientist]
[Edited on 4-9-2017 by Alienrocketscientist]
hissingnoise - 4-9-2017 at 12:14
Your double-post seems mostly nonsensical ─ perhaps you should hit delete and try again?
XeonTheMGPony - 4-9-2017 at 13:29
add to a 14 year old post <_<