mbeef
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Aluminium-Mercury Amalgam
I did a bit of research around the subject and I didn't really find a direct answer to my question, so here I am.
In solution, do all mercury salts form an amalgam with aluminium? eg - Mercury(I) Nitrate
In almost all of the examples I have seen HgCl2 as the salt, an occasionally Hg(NO3)2. Is there any reasoning behind
this? Safer, faster, cheaper? Does the oxidation state of Hg change anything?
I don't see why all Hg salts wouldn't all act the same, the mercury in the salt should react similarly unless some salts are more energy favourable
than the resultant amalgam? Please enlighten me 
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elementcollector1
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I'm not sure what you mean. If you had a mercury salt in solution, and added aluminum, it would precipitate elemental mercury, which may form an
amalgam with the remaining aluminum only to lose the Al back to any remaining mercury salt. Excess aluminum would create an amalgam.
Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
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12AX7
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Chloride might be more corrosive to aluminum, which is the case with copper (copper sulfate hardly reacts with aluminum; copper chloride reacts
autocatalytically).
Just comes down to aluminum's pesky oxide layer.
Tim
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Eddygp
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Chloride is definitely more corrosive with aluminium (especially when used together with copper cations), so therefore, after attacking the aluminium,
mercury metal will form and react with the rest of the aluminium to make the amalgam. So for example:
3HgCl2 + 2Al ==> 2AlCl3 + 3Hg
3Hg + nAl ==> amalgam
You should therefore add Al in excess for the first reaction, or if you just want mercury metal and that's it, add mercury(II) chloride in excess.
there may be bugs in gfind
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IrC
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"Just comes down to aluminum's pesky oxide layer."
I found by experimenting you can get at Al without dealing with the oxide layer by first dissolving it in Ga. I still have a few ounces of this in an
airtight bottle which is both very odd and cool at the same time. If you wrap a chunk in a wet paper towel it produces heat and H2 by ripping apart
the water. A large enough piece and it gets so hot the towel starts burning. Stores for years quite well if you keep it away from air and extremely
dry. The result is what I believe is the hydroxide of Al and as an added bonus you recover nearly all of the Gallium as beads of liquid metal.
"Science is the belief in the ignorance of the experts" Richard Feynman
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Mesa
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Hence why gallium is often used as a non-toxic substitute for mercury in such reactions... Albeit with somewhat limited success.
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