The_Davster
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Ammonium Nitrate detonation in solution...impossible...or is it?
This is a story of how boredom in the lab either leads to disaster, discovery or both.
Well a few days ago I was bored in my lab, my new order of chems had not came yet so I had nothing to do. I had many bottles of reagents with very
little in the bottom just lying around. Out of sheer boredom I think to myself, "hmm I wonder what happens if I mix a little bit of each powder
I have lying around and add water"- a stupid idea of course. So I proceed to mix a sprinkle(a highly precise scientific measurement  ) of the following reagents in a 100mL beaker. Citric acid, magnesium sulfate,
calcium chloride, sodium hydroxide, ammonium nitrate(prilled 3-4mm only about 8 prills total added), calcium hypochlorite, strontium sulfate,
potassium permanganate, oxalic acid and magnesium hydroxide. The total volume of all this was a bit under 10mL's. So then I proceed to put this
beaker under the tap. I added about 10mL of water. A few wisps of white fumes came off so I started the wafting method of smelling chemicals when
BOOOOOOOOM, purple and brown solution sprayed everywhere-onto my hand which happed to be exactly over the beaker at the time. I jumped back in alarm
and the solution again made two more sharp bangs-spraying more purple stuff everywhere. I then decided to add lots of water to flush it all out of
the beaker. while I was reaching for the knob it made 3-4 more loud bangs. I managed to fill the beaker with water and the beaker stopped exploding.
I glance aroung there is permanganate blobs everywhere and the entire room smells like chlorine and ammonia.
Although it goes against everything I know about energetics, is it possible that the ammonium nitrate detonated in solution? I mean, 7 bangs and 8
prills of ammonium nitrate, coincidence? Well I am not sure if it was or was not the NH4NO3 detonating does anyone have any other ideas on what was
making the bangs? I have no other possible ideas. Also the beaker now has several small pitmarks/craters in the bottom.
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DDTea
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You said there was an Ammonia smell... Just from looking at that, the following reaction MIGHT have occurred:
OH- + NH4+ --> NH3(g) + H2O
I have done this before to make Sodium Nitrate solution from NH4NO3 and NaOH. You had a lot of sulfates and chlorides in there, so I'm going to
make the ASSumption that they did not react with each other. So, that leaves Citric Acid, Potassium Permanganate, Calcium Hypochlorite Magnesium
Hydroxide, and Oxalic Aid.
Potassium Permanganate is a rather aggressive oxidizer, so it might have reacted badly with the Citric Acid and Oxalic Acid... The heat from the
reaction might have vaporized some Cl from Ca(OCl)2. Now, the white fumes could have been the result of the NH3 and the Cl gas reacting to form NH4Cl
(this is a common classroom demonstration reaction, showing the rates of dispersal of HCl and NH3 gasses in a tube).
Don't know what the pops and explosions were from.... I don't think it was NH4NO3 detonating, because wouldn't that form N2 and H2O,
and not NH3?
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The_Davster
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I realize that the ammonia was from the ammonium nitrate reacting with the NaOH, I have used this many times as an ammonia generator. The chlorine
may have been formed from one of the acids reacting with the hypochlorite to yield chlorine, or from the reaction heat as mentioned by Samosa. But
the multiple explosions still mistify me.
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madscientist
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Hypochlorite will react with ammonia to form nitrogen trichloride. Ammonia was created by the mechanism Samosa mentioned.
I weep at the sight of flaming acetic anhydride.
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froot
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Have you ever mixed dry hypochlorite and NH4NO3 together? After a while it does the same thing. I'm sure there was much other unhappiness in that
poor beaker and the I'm assuming the hypochlorite was the one that sent the unhappiness all over your lab. 
Rogue your name is officially appropriate. 
We salute the improvement of the human genome by honoring those who remove themselves from it.
Of necessity, this honor is generally bestowed posthumously. - www.darwinawards.com |
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darkflame89
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Look, here's what i found:
Calcium hypochlorite (bleaching powder) Shake 20 g calcium hypochlorite into 100 mL water for several minutes, then filter. Add 10 mL conc. ammonia
and heat mixture. Use extreme caution! Chloramine and explosive nitrogen trichloride may be produced. Displacement of air. 2NH3 + 3CaOCl2 --> N2 +
3H2O + 3CaCl2
Ignis ubique latet, naturam amplectitur omnem.
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