I am in need of a couple of grams of HgCl2 for an upcoming project...Unfortunately, it'd cost me ~$10/g after shipping and hazmat fees. Elemental
mercury is almost as bad, save the near impossibility of finding it.
It is, however, quite easy to come by old tilt switches and thermometers. My question is, does anyone have any idea how much mercury is in them?
I've seen thermometers break and form tiny globules of mercury, but have never had a chance to find out how much is in one. Similarly, I have
handled thermostat tilt switches, but have never cracked one open. I'd imagine used switches (~$6/piece, could probably find them cheaper) would be
cheaper per gram, but I have no basis for this assumption other than examining them externally. Aside from these, is there a better source for
non-hazmat mercury?
Also, has anyone here prepared the chloride from the metal? I'm thinking boiling HCl might do it, but I don't know if mercury is reactive enough to
work. I vaguely remember forming it via redox as an indicator in a chem lab last year, but I'm not sure if the process would be viable for my
purposes.
Similarly, it is my understanding that it is the free Hg++ ion that "infiltrates" the Al2O3 layer in an AL/HG reductive animation. Is it possible to
use another salt, possibly the nitrate or the sulfate? I have only ever seen the dichloride in the literature, is there a reason for this other than
availibility?
Thanks in advance for any advice...Nick F - 14-12-2006 at 11:25
A thermometer or two will have enough for a few grams of chloride I'm sure.
There is a thread on making the chloride. Basically, you dissolve the mercury in nitric acid, heat this to form the oxide, and react that with conc
HCl. HCl won't dissolve mercury on its own, you would need an additional oxidiser. Hot sulphuric acid would probably also dissolve mercury if you
don't have nitric acid.
I have about 100g of mercury of unknown purity which I don't need if anyone is looking for some, by the way... (I also have almost a kg of triple
distilled, if anyone really needs some pure mercury, but I'd rather get rid of the stuff of unknown purity first).woelen - 14-12-2006 at 12:09
If the mercury of unknown purity is liquid and has a nice shiny mirror, and it does not stick to the glass, then it still is quite pure, and it will
be at least 99% or so. Good enough for making HgO and then HgCl2.
[Edited on 14-12-06 by woelen]Intergalactic_Captain - 14-12-2006 at 12:30
The Hg->HgO->HgCl2 sounds like it'll work out quite nicely. Thanks.
And Nick F., whereabouts on the purity scale could that 100g be? 90%+, or just miscellaneous crap that's somehow liquid? I'd rather not distill it,
but if you think it's pure enough to make the chloride as-is I'd be happy to take it off your hands...Provided it's cheap and you don't believe in
hazmat. Eclectic - 14-12-2006 at 15:29
Anything less than 1 fluid oz (13.5 actual oz) should be ok to ship hazmat fee exempt, ground only. Older USPS rules specified containers of 1lb or
less, ground only.Darkblade48 - 14-12-2006 at 15:56
It's too bad you probably wouldn't be able to ship that mercury over to Canada. I don't think customs would take too kindly to finding mercury in
envelopes Baphomet - 14-12-2006 at 16:11
A few points from my private notizbuch:
HgCl2 is used most often because of it's high solubility. Any other Hg salt with good solubility could be used (most however do not have good
water solubility).
Two alternatives you could use are mercuric nitrate and mercuric acetate
Purity of the metal is of no concern if it is only being used for amalgamation. Some impurities are lost during the process of forming the
salt, and the others will not likely hinder the forming of amalgam
A most commonly published route to HgCl2 is:
Hg > HgSO4 > HgCO3 > HgCl2
..which works fine but is a time-consuming and inconvenient approach (in that it requires 95% sulphuric acid)
A better approach is to gas Hg with Cl2 then add distilled H2O and leave the jar in the sun for a few weeks. Insoluble Hg2Cl2 is converted to
Hg and HgCl2. The latter enters solution and the former is easily separated for re-processing. A write-up on this will be forthcoming.
Prior art postulated that Hg2Cl2 works for amalgamation but this is incorrect due to the substance being almost totally insoluble. More likely
some HgCl2 was present due to an excess of Cl2 when the elements were combined.
Baphomet - 14-12-2006 at 16:18
Before I forget, does anyone know how the hazmat rules work with regard to mercury-containing devices? For instance, what are the rules for posting
electronic devices like tilt switches?Magpie - 14-12-2006 at 18:31
Baphomet says:
Quote:
HgCl2 is used most often because of it's high solubility. Any other Hg salt with good solubility could be used (most however do not have good water
solubility).
You say mercuric acetate or mercuric nitrate can be substituted for HgCl2. Do you happen to know if this holds true for the synthesis of pinacol from
acetone? I have a procedure that specifies HgCl2 as catalyst for this.Baphomet - 14-12-2006 at 19:25
Maybe
After a quick look at http://www.orgsyn.org/orgsyn/prep.asp?prep=cv1p0459 I'm guessing that the nitrate will be fine. The acetate might work but the yields would likely
be lower due to the kinetics being hindered by the big acetate ions [it's formula is Hg(C2H3O2)2]Magpie - 14-12-2006 at 21:22
I'm just wondering because another experiment (an oxymercuration) in the same book specifies Hg(CH3COO)2, which is what I happen to have. I don't
know if the pinacol actually needs the HgCl2 or if the authors were just lazy in not specifying the same Hg compound for both. I could always just
try it and see, but hate to take the risk of wasting a somewhat expensive chemical and unnessarily creating Hg waste.
I was thinking that I would make HgCl2 through the Hg acetate ---> HgO ---> HgCl2 route if I really want to do this pinacol synthesis. It also
calls for a septum, glass syringe, and hypodermic needle, which I don't yet have either.Baphomet - 14-12-2006 at 22:12
Sure try it out. Since they didn't specify, you're basically conducting research at this point
Check your reference. Maybe they're using silly little microscale flasks and things, hence the syringe? Or is the reaction performed in an inert
atmosphere?Eclectic - 15-12-2006 at 05:57
To make pinacol, you just need a soluble Hg salt to amalgamate the Mg turnings. Other reactive metals (Al, Zn) might work also?garage chemist - 15-12-2006 at 06:11
Dissolve a drop of mercury in hot HNO3 (65%), basify the solution with NaOH. HgO will precipitate and is filtered off.
This can then be dissolved in any acid, oxidising or not, that you wish. BromicAcid has done it and it is the best way to make Hg salts.
I find that HgCl2 is a bad choice for an amalgamation, since it partially gets reduced to the insoluble Hg2Cl2 and some mercury gets wasted that way.
I'd use a mercuric nitrate or acetate solution instead of HgCl2 for amalgamation- but it must be nearly neutral or only slightly acidic, so you should
dissolve HgO in the stochiometric amount of HNO3 or AcOH and not use the solution resulting from dissolving the mercury.
For dissolving the mercury, hot conc H2SO4 under reflux can also be used (it gets reduced to SO2), but a lot of mercury vapors will be generated if
you dont use a reflux condenser.Magpie - 15-12-2006 at 09:54
The hypodermic and septum are used for keeping an inert atmosphere for the pinacol synthesis. As noted, Mg is also required. The Hg is supplied by
HgCl2.
In the oxymercuration of an alkene the mechanism is shown. Here the Hg(OAc)2 dissociates to Hg(OAc)+. It then bridges the double bond of the alkene,
creating an electropositive center for nucleophilic attack. So perhaps, Hg(OAc)2 is not appropriate for reactions requiring amalgamation like the
pinacol. Hence the use of HgCl2 instead. Does this make sense?garage chemist - 15-12-2006 at 10:50
No, it doesnt matter which mercury salt you use.
If amalgamated aluminium is the reactant, the Hg salt will be completely reduced to the metal before any other reaction will start because of the huge
difference in redox potential between aluminium and mercury.Nick F - 16-12-2006 at 07:41
"If the mercury of unknown purity is liquid and has a nice shiny mirror, and it does not stick to the glass, then it still is quite pure, and it will
be at least 99% or so. Good enough for making HgO and then HgCl2."
Yeah, it's shiny, liquid, and doesn't wet glass. There's a bit of oxide on it, but that's easy to clean up by letting it drip through a small hole in
a filter paper.pantone159 - 18-12-2006 at 00:25
Quote:
Originally posted by Intergalactic_Captain
Is it possible to use another salt, possibly the nitrate or the sulfate? I have only ever seen the dichloride in the literature, is there a reason
for this other than availibility?
According to Shakashiri, Chemical Demonstrations 4.1, mercury(II) nitrate is extremely hygroscopic. That is likely a reason it isn't used much, it
would work but is more hassle.picketfence - 22-1-2007 at 17:02
industrial Mercury displacement relays, the amount of Hg depends on the number of poles, but it'll usually be in the 100's of grams.
Check Ebay.rockjet - 23-1-2007 at 08:36
How about using the pigment vermilion or cinnabar as a mercury source? Chemically it's mercury(II) sulfide. Elemental mercury can be extracted from it
simply by heating the sulfide.
Perhaps one could go straight to mercury(II) chloride by treating the sulfide with hydrochloric acid, but I'm uncertain about this method.garage chemist - 23-1-2007 at 12:57
Simply heating the sulfide will make it sublimate and nothing else. I've done that.
In order to extract mercury, either you have to administer air to the heated sulfide or mix the sulfide with iron powder prior to heating.
And the sulfide is insoluble in every acid. Only aqua regia can dissolve it slowly by oxidising the sulfide.
But with HCl, no chance of any reaction.
[Edited on 23-1-2007 by garage chemist]Maya - 23-1-2007 at 16:21
GC, converting the sulfide is not an obvious problem at all. The real problem is who even sells or carries vermilion or cinnabar at all anymore?
makes the whole point moot........UnintentionalChaos - 23-1-2007 at 21:21
Well, I have some old tubes of real vermillion oil paint (still usably soft and probbaly in lead tubes, no less), but I don't plan on removing the
sulfide from them. The cost of the stuff is so high, assumedly significantly more than the cadmium red replacement (still not remotely cheap), that
searching for some other source of Hg is necessary. Authentic vermillion paint from the company that is from (long discontinued item)could probably
snag at least $80 US per tube and potentially much more. Their currently available cadmium reds are $35-40 a tube for reference.garage chemist - 23-1-2007 at 22:34
Yes, thats true. I know an artist store where cinnabar can still be got, but at an exorbitant price. It would be cheaper to buy tilt switches instead.nannah - 26-7-2014 at 15:51
Hi, guys. I got an offer buying virgin Hg 99,999% . And i dont know what they usually charge, but the price of 50 grams is about 75 €, and 100 grams
is 130 €. They also sell 1 and 5 gram capsules.
Should i go for it? I know how difficult it is for people to get it nowdays, so thats why i considering buying some, for future experiments. I may
never get the opportunity again.
Thanx in advance. gdflp - 26-7-2014 at 17:35
If you want a small sample for an element collection, then go for it. But if you want to make mercury compounds, Praxichys is selling mercury for a
much better price, though it's not 5N, that's not really necessary when making compounds.Praxichys - 26-7-2014 at 17:46
If you want a small sample for an element collection, then go for it. But if you want to make mercury compounds, Praxichys is selling mercury for a
much better price, though it's not 5N, that's not really necessary when making compounds.
Old thermostats. An antique Mercury sphygmomanometer. Some of your older Sphygmos pack a lot of mercury. Keep your eye out for one. A garage sale,
a thrift store, a flea market......such items appear in these places. Sometimes cheap. Good way to pick up a lifetime supply of Mercury.Bert - 5-8-2014 at 18:57
A long time ago, several Mercury vials from tilt switches provided all the Mercury metal I have ever needed. Look over old steam heating boiler
controls such as "vaporstats" or mercury filled contactors, quiet switches, older cars with tilt switches that turned on trunk or under hood lights
when the hood or trunk lid were raised .Manifest - 6-8-2014 at 11:03
A long time ago, several Mercury vials from tilt switches provided all the Mercury metal I have ever needed. Look over old steam heating boiler
controls such as "vaporstats" or mercury filled contactors, quiet switches, older cars with tilt switches that turned on trunk or under hood lights
when the hood or trunk lid were raised .
Tilt Switches are controlled here because the IRA make bombs with them.careysub - 6-8-2014 at 21:27
A long time ago, several Mercury vials from tilt switches provided all the Mercury metal I have ever needed. Look over old steam heating boiler
controls such as "vaporstats" or mercury filled contactors, quiet switches, older cars with tilt switches that turned on trunk or under hood lights
when the hood or trunk lid were raised .
Tilt Switches are controlled here because the IRA make bombs with them.
Hmm... about as pointless as Texas banning beakers.
There were around 10,000 IRA bomb attacks during "the troubles". I'm sure the run came to an end because they had no more tilt switches.
