anybody know some reasonably easy to obtain chemicals that would yield NO2(g)?BromicAcid - 1-8-2004 at 19:07
Air is going to be the most readily obtained chemical mixture that can yield NO2, however you are going to have to make an investment in equipment to
process your feed stock. Oxidation of ammonia with a platinum catalyst or copper is also an option, there is more information on that here too.
Otherwise you are going to most likely either need nitric acid (reacts with nearly any metal when concentrated to yield NO2 [except it's initial
reaction with the alkali metals and alkali earths]) or you are going to need to decompose nitrate salts with high temperatures. The alkali metal
nitrates decompose to give primarily oxygen and many of the alkaline earths give mostly oxygen, although as you move down the group the NO2 percentage
goes up. Your best bet is going to be a heavy metal salt though, traditionally Pb(NO3)2 (Could be Pb(NO3)4, I forget) is used in lab to generate NO2,
be warned though the lead monoxide that you are left with will attack your glassware in the state that it comes into being in.
Be forewarned that NO2 is exceedingly toxic, there are some threads here warning of the toxicity already though. It can kill you
without warning and is not good for your lungs at all. Decomposing some nitrate salts, could lead to an explosion, molten nitrates are highly
oxidizing.
More information could be given if you would have given information regarding the purity of the product that you were looking for or maybe a list of
chemicals you might have at your disposal.
[Edited on 8/2/2004 by BromicAcid]budullewraagh - 1-8-2004 at 19:39
Quote:
Be forewarned that NO2 is exceedingly toxic
of course; it's nitric anhydride
i suppose my best way would be to oxidize NH3. for the oxidizing agent, how about some good ol' supersaturated HCl?BromicAcid - 1-8-2004 at 19:48
HCl is not normally an oxidizing agent, it will not work for oxidizing ammonia, expecially in solution.
NO2 is not nitric anhydride, N2O5 is. NO2 reacts with water thusly:
that's a shame. i dont suppose an alkaline solution would work either since there are some cations involved.
with this in mind, are you familiar with any reasonable means for making N2O5?The_Davster - 1-8-2004 at 22:17
Coincidently I just read about N2O5 today and the book is still right here.
From "Inorganic Chemistry":
"Nitrogen pentoxide, the anhydride of nitric acid, cannot be obtained synthetically from the lower oxides of nitrogen since it is too easily
decomposed. It can, however, be obtained if chlorine is passed over solid silver nitrate, when NO2Cl is formed, which then gives nitrogen pentoxide
with the excess nitrate:
NO2Cl + AgNO3--(-AgCl)-->N2O5
N2O5 may also obtained by dehydrating nitric acid: 2HNO3--> N2O5 +H2O. This dehydration must be carried out by the introduction of phosphorous
pentoxide at the lowest possible temperature, on account of the ease with which N2O5 is decomposed. The N2O5 formed is distilled off by gentle heat.
N2O5 forms colorless, transparent hygroscopic crystalls which may be kept fo ra long time at low temperature, but which gradually decompose
irreversibly at room temperature, thus: N2O5-->2NO2+O. It has a vapour pressure of 1 atmosphere at 32.5C and sublimes without much decomposition;
it sometimes decomposes spontaneously with explosion. The gradual but complete decomposition of nitric acid is due to the presence of small
quantities of free N2O5."
[Edited on 2-8-2004 by rogue chemist]atombum - 4-8-2004 at 20:36
Easiest route to NO2- nitric acid and copper. Even easier still, there's nothing simpler than tossing a penny in some nitric to release NO2.
Heed the aforementioned warnings though, the first time I made NO2, I wanted to find out how it smelled. Sniffed the calmed mixture a few times,
couldn't smell much of anything except a slight chlorine odor, so the concentration couldn't have been that high. For the next couple of
days I felt a moving, tickling sensation in my throat/chest area. No doubt fluid moving from a mild pulmonary edema. Not much of a poisoning,
however I barely passed the odor threshold.hodges - 6-8-2004 at 14:51
You could add an acid to a nitrite (NOT nitrate) and that will give you NO, which will react with oxygen in the air to form NO2. If you don't
have any nitrites handy you can try your luck at making them from nitrates. If you heat potassium nitrate just the right amount supposedly you get
oxygen and potasium nitrite, although I tried this several times without luck back when I was in high school.chochu3 - 6-8-2004 at 15:46
Reduce nitric acid with hydrogen iodide will create HNO2.budullewraagh - 6-8-2004 at 16:11
problem is that i wanted to make nitric by bubbling the anhydride into solutionTheoretic - 20-10-2004 at 01:31
One could acidify with a strong mineral acid a 1:1 mix of nitrite and nitrate to make NO2.
Decomposition of Mn(NO3)2 will give you O2-free NO2:
Mn(NO3)2 => MnO2 + 2NO2
Decomposition of Pb(NO3)2 can be done in glass vessels, with SiO2 as a flux to form lead silicate, to prevent glass corrosion.
Dissolving Cu in HNO3 is a good method, then you could dehydrate it and decompose for more NO2 (although on dehydration it will partially decompose to
a basic nitrate).
As I mentioned some time ago in another thread, heating slaked lime with AN to form Ca(NO3)2 and then decomposing that will work. Dissolving iron in
molten AN and decomposing the iron nitrate will also work.
