guy - 14-2-2006 at 20:33
1> I am trying to find ways to oxidize ammonium salts to nitrogen. Will ozone oxidized ammonium ions to nitrogen leaving behind the acid of the
anion?
O3 + (NH4)X => N2 + H2O + HX
2> Also, I tried oxidizing ammonium sulfate with sodium hypochlorite soln. bleach. Along with vigourouse bubbling (N2, my desired product), it
gave a very pungent odor that smells like bad, rotten fish. It does NOT resemble ammonia at all. Does anyone have any idea what the smell is?
Microtek - 15-2-2006 at 03:41
Be careful with adding ammonium salts to bleach. The strongly alkaline solution will give you ammonia which is then oxidized to hydrazine by the
NaOCl. Most of it will likely react with air to form water and nitrogen, but you will be exosed to at least some hydrazine ( which is strongly
carcinogenic ).
With regards to converting ammonium to nitrogen, I know from personal experience that mixtures of ammonia and N2O are quite flammable, but you could
also simply burn it with air under suitable conditions ( and with suitable catalysts ).
garage chemist - 15-2-2006 at 04:52
The best known and most effective way to oxidise ammonium to nitrogen is adding a nitrite.
NH4+ + NO2- -----> N2 + 2 H2O
The solution has to be heated in order to effect a complete reaction, but it already slowly takes place at room temperature.
NaOCl can do a variety of things to ammonium ions, either oxidise it to hydrazine (when a large excess of ammonia is present), or to nitrogen (an
always occuring side reaction in the production of hydrazine, which becomes the primary reaction under suitable conditions, specifically with
stochiometric amounts of NaOCl and ammonia under basic pH and heat).
The third possibility is the formation of chlorinated amines like nitrogen trichloride (under not so strongly alkaline conditions), which was the
strong pungent smell you described. It's also very toxic and explosive. Don't do that again!
[Edited on 15-2-2006 by garage chemist]
guy - 15-2-2006 at 15:11
Ozone in neutral aqueous solutions is a stronger oxidizing agent than hypochlorite so it should oxidize NH4+ to N2 and water and hydronium ions. If
anyone has an ozone generator and some ammonium salt, can they try it and see if any acid is left behind? Theoretically it should work.
guy - 19-2-2006 at 22:47
I tried mixing KMnO4 with ammonium hydroxide solution to see if any N2 forms. No gas was formed nor was any MnO2 produced. I got the idea from
looking at the reduction potentials on http://www.webelements.com/webelements/elements/text/N/redn.... Why would the reaction not work?