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Author: Subject: NO2 => HNO3 ?
flakten
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[*] posted on 16-5-2012 at 19:56
NO2 => HNO3 ?


Hi, I'm new on the forum so I hope this post went in the right place.

I'm doing some research (library and a bit of internet searching) on the subject NO2 and N2O4

I've hit a snag, question; how do you proceed with making liquid N2O4 (NO2 respectively) into nitric acid. I am uncertain of the energy and entropy of the reactions. Several reactions have been suggested to me:

1.Add liquid NO2 to distilled water, this should result in 2 NO2 + 2 H2O => 2 H2NO3 => 2 H+ + 2HNO3-
2.Naa, that wont work, but if you heat it it will react as above
3.Naah, you need a catalyst as well, palatinum should work
4.Naah, you need to add it to hydrogen peroxide which per gram costs a fortune so it's not worth it. (H2O2 is only sold in 3% solution in EU, 500 g of this costs 2 eur and {0,03*500 g =15 g, 2 eur / 0,015 Kg = 113 eur/Kg, i.e. a small fortune) 2 NO2 + 2 H2O2 => 2 H2NO3 + O2 => 2 HNO3- + 2 H+ + O2

So now I need help, which of the above is true?
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hissingnoise
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[*] posted on 17-5-2012 at 03:05


Quote:
I've hit a snag, question; how do you proceed with making liquid N2O4 (NO2 respectively) into nitric acid

Being a mixed anhydride, chilled N<sub>2</sub>O<sub>4</sub> added to water would likely form a bottom layer of ~100% HNO<sub>3</sub>; the top half should mostly consist of HNO<sub>2</sub> with dissolved NO<sub>2</sub>.
Dissolved NO<sub>2</sub> can be oxidised by sustained bubbling of dry air, or better, dry oxygen through the soln..
Do you have access to N<sub>2</sub>O<sub>4</sub> in quantity?

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barley81
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[*] posted on 17-5-2012 at 04:46


Here is information from "Absorption of Nitrous Gases" in the SM library:


[Edited on 17-5-2012 by barley81]

nitrogen tetroxide.png - 177kB
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hissingnoise
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[*] posted on 17-5-2012 at 06:50


I'd expect stoichiometric quantities to react more or less as I've outlined . . .

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