directortelemachus
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Unknown Copper Reaction
I shoot firearms on a fairly regular basis and to this end I keep a large supply of Hoppes No. 9 bore cleaner on hand. The bottles that No. 9 comes in
are rather large so I tried putting some into a small, clean oiling can. I came back a few days later to find that the No. 9 had reacted with the
brass of the oiling can and created a rather beautiful green solution. Curious to see if I could replicate the reaction, I poured ~100 mL of the No. 9
into a beaker and placed a single copper (pure) penny in with it. I let the solution sit for a couple of days and returned to find out that indeed,
the reaction appeared to have repeated itself. I let this sit for a few more days to ensure a complete reaction. This evening I was sitting at my
workbench wondering what exactly what the solution might be and what it might react with. I tried mixing it with a few other things, and found that it
reacted again with sulfuric acid (93%), creating a reddish brown liquid. What I found particularly interesting was that when I went to neutralize the
solution with a sodium bicarbonate solution, it reacted extremely exothermically and produced a deep purple precipitate.
I was wondering if anyone might have some thoughts on what might be going on here. Below I have included the MSDS for Hoppes No. 9 bore cleaner. I am
pretty sure that I can figure out what is happening in the latter part of the reaction, however I'm not so clear on what is happening with the No. 9
at the beginning. I would appreciate any help.
http://www.hoppes.com/Hoppes/files/9d/9dc3db35-232c-4353-bc5...
Addendum: After completely washing the solution in a sodium bicarbonate solution the deep purple color went away. The solution that was left was was
clear and colorless.
[Edited on 14-7-2016 by directortelemachus]
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TheMrbunGee
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This is composition of No. 9
1 Ethanol 15 ‐ 40 %
2 Kerosine (Petroleum) 15 ‐ 40 %
3 Oleic Acid 15 ‐ 40 %
4 Amyl Acetate 5 ‐ 10 %
5 Ammonium Hydroxide 1 ‐ 5 %
I don't have the knowledge of any of this stuff reacting with copper metal and forming green salt. Both - the acetate and hydroxide are blue. So there
is more complex stuff going on and ingredients co-op to make the green stuff.
Was the red solution clear?
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directortelemachus
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No, the red solution was was opaque. There seemed to be some sort of precipitate in the solution. For what it is worth, No. 9 is supposed to help with
coper fouling from jacketed bullets.
[Edited on 14-7-2016 by directortelemachus]
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TheMrbunGee
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Red one is copper (I) oxide.
When adding NaHCO3 - violent reaction is probably it reacting with H2SO4, but I can’t explain the purple color..
Cu2O (red) reacts with H2SO4 to form CuSO4 (blue).
I could assume that Ammonium Hydroxide was still in the solution so it formed complex of some Copper salt, but not CuSO4, because it is deep blue.
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Melgar
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Quote: Originally posted by TheMrbunGee  | Red one is copper (I) oxide.
When adding NaHCO3 - violent reaction is probably it reacting with H2SO4, but I can’t explain the purple color..
Cu2O (red) reacts with H2SO4 to form CuSO4 (blue).
I could assume that Ammonium Hydroxide was still in the solution so it formed complex of some Copper salt, but not CuSO4, because it is deep blue.
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Could be a mixture of the red oxide and the blue ammonia complex, perhaps?
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TheMrbunGee
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Was the purple one clear? if not, then it might be!
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directortelemachus
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The purple solution was very opaque. The color seemed to come from suspended purple particles.
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TheMrbunGee
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Then those might be just red copper oxide particles in a blue copper solution!(Or red oxide and blue copper carbonate suspension)
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Texium
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Thread Moved
23-8-2016 at 08:36 |
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