Sciencemadness Discussion Board - Mercuric Salts

Mercuric Salts

sirius_cm - 17-5-2003 at 14:45

So I've obtained some Mercuric salts, HgO, Hg(NO3)2, and HgSO4.

Here is my delimm I want the mercury, pure stuff, all I need is a reaction to happen, and im thinking activity series.

In all of my searching on google, all I find is that This shit is dangerous, and I know this, also, It says that the salts decompose in reaction with light. I'm not gonna heat this stuff, because even though I know it will decompose, i cant control the vapor. Any suggestions?

Basicly, I want to extract the mercury from the salts.

sirius_cm - 17-5-2003 at 14:58

Anything would be helpful, Im thinking of Zinc for a replacement reaction. Make Aqueous solutions of each and mix...

Blind Angel - 17-5-2003 at 15:04

I know you dont want to heat but electrolysis may be an option, look in sodium isolation thread (or something like that) for more info

madscientist - 17-5-2003 at 15:04

The best option unfortunately involves generating some Hg vapor: convert your salts to Hg(OH)2 via mixing with NaOH solution and filtering out the Hg(OH)2 precipitate, then heating to dehydrate to HgO, and then heating further to liberate oxygen, leaving Hg metal. It's clearly something that should be done outside or under a fume hood.

Other options would be much more difficult; one would be converting it all to Hg(NO3

2, then reacting with an alkene (it adds to the double bond), and then reducing with NaBH4, liberating Hg metal.

Replacement with a more electropositive metal will not work. You'll just form an amalgam.

Blind Angel added a good thought. You could try electrolysis with an iron cathode (don't use a different metal or it'll likely amalgamate) and a graphite anode.

[Edited on 17-5-2003 by madscientist]

sirius_cm - 17-5-2003 at 15:10

Well i have some HgO, Now, me, an amateur, do not really have access to some lab at my school or anything, and I want to do this reaction, because mercury is my favorite element

I know this stuff decomposes at around 400 C.

So how should I attack this problem? Me myself, i dont wanna kill myself, after reading all the stuff on mercuric salts, I almost pissed my pants, but I keep thinking about How Lavioseir did his experiments, and he didnt just pass out and die....

sirius_cm - 17-5-2003 at 15:11

And when i was snooping, i found this:

Mercury salts when heated with Na2CO3 yield metallic Hg and are reduced to metal by H2O2 in presence of an alkali hydroxide.

So does this mean, possibly, that I can use H2O2 and some NaOH on these salts to get the metal?

sirius_cm - 17-5-2003 at 15:14

This electrolysis perhaps could be an option, now i have HgO, Hg(NO3)2 and HgSO4. Make a aqueous solution then complete circuit?

Edit: I know they also decompose with light, does this mean, i could theoretically set it outside and let it decompose over like a week or so?

[Edited on 17-5-2003 by sirius_cm]

madscientist - 17-5-2003 at 15:25

Yes, that's essentially all there's to it. Just make sure that you're using iron as the cathode (positive) and graphite as the anode (negative). If Hg is liberated, it'll sink to the bottom of the electrolysis vessel as its density is 13.53g/cm3.

Quote:

Mercury salts when heated with Na2CO3 yield metallic Hg and are reduced to metal by H2O2 in presence of an alkali hydroxide.

Up to "yield metallic Hg" it all makes sense. Mixing a mercuric salt with sodium carbonate would yield mercuric carbonate, which would successively decompose to mercuric oxide and then mercury metal upon heating. The second part, however, strikes me as being meaningless babble.

I believe the decomposition of mercuric salts upon exposure to light would be far too slow for your purposes. I've had HgBr2 exposed to sunlight for weeks without notable decomposition.

[Edited on 17-5-2003 by madscientist]

sirius_cm - 17-5-2003 at 15:30

one last question, which compound do you think would be the best for the job of electrolysis? HgO, Hg(NO3)2, or HgSO4?

madscientist - 17-5-2003 at 15:35

Hg(NO3

2.

Blind Angel - 17-5-2003 at 22:36

[almost out of topic]
one of my old teacher told us to not sniff mercury vapor or you will stay with sequel all the rest of your life (yes he did it...)
[/almost out of topic]

I am a fish - 18-5-2003 at 00:55

Couldn't mercury be displaced from a Hg(NO3)2 solution by aluminium? If the resulting amalgam was exposed to air, the aluminium would rapidly oxidise (due to the mercury disrupting the unreactive oxide layer) and float to the surface.

elemental Hg

jimwig - 18-5-2003 at 15:43

I have been fortunate to encounter discarded mercury more than once.

All old house thermostats have a mercury switching device - these are often discarded.

I have found mercury at metal recycling operations - they gave it to me after I asked how much it was.

Mining supply outfits will sell you elemental Hg - miners still use it occasionally to amalgamate with gold and pgm's.

Keep your eyes open. It's around.

don´t waste the precious salts !

Organikum - 19-5-2003 at 08:46

find your mercury here

If you now don´t find it - you´ll never find it.

Best is of course to buy an old lighttower - the lights swim in mercury (turning round and electricity - ya know...). Several hundred kilos often. Thats it!

jimwig - 20-5-2003 at 07:04

Organikum--- that's a good site. There is little or no data concerning the actual extraction of Hg from the devices,etc.

Physical, chemical and spiritual techniques, eh?

Had a slight chance of becoming involved in a major cleanup of mercury on the southeastern coast a few years ago. Seems that metallic mercury has been lost due to an electrolytic process with NaCl - forget the name of process.

Anywho years of processing resulted in a significant amount mixed with bottom soils of the area (tidal creeks and salt marshes) and the state and fed EPA wanted to clean it up. I suggested they dredge it up - not large scale but with the type of suction dredge operated by recreational miners. They were interested but I never followed up.

I think the director of the project estimated hundreds of tons of elemental mercury lying on the bottom. (not tomention all the already assimilated methylated forms in plants and animals).

Organikum - 20-5-2003 at 17:01

Extraction?
I suggest to break open the glass vial where it is sealed (regarding all necessary safety needs, do it over a bowl or else) and thats it.
The contacts in the vials of the electric switches are made of or coated with some tungsten or else - perfect for spark gaps.

GZAust - 11-7-2003 at 07:25

>>Up to "yield metallic Hg" it all makes sense. Mixing a mercuric salt with sodium carbonate would yield mercuric carbonate, which would successively decompose to mercuric oxide and then mercury metal upon heating.

madscientist, which is one single step of heating to end up with elemental Hg.

But I'm sure youd have to be really careful of the mercury vaporising too.

What is the eucletic temparature of trhe Hg salt and sodium carbonate over the 400C for regular lone decomposition of a Hg salt?

Are Hg salts hard to come by?

kryss - 15-7-2003 at 13:50

This method works for reducing silver chloride to silver - it probably has a good chance of working for insoluble mercury compounds like the hydroxide/oxide:

Dissolve 500 g glucose in a couple litres water chuck in some Aluminium foil , then add your HgO - its works slowly with continuous strirring over a period of days.

sirius_cm - 22-7-2003 at 16:04

Quote:

Originally posted by kryss
This method works for reducing silver chloride to silver - it probably has a good chance of working for insoluble mercury compounds like the hydroxide/oxide:

Dissolve 500 g glucose in a couple litres water chuck in some Aluminium foil , then add your HgO - its works slowly with continuous strirring over a period of days.

interesing... can anyone verify this or explain the mechanics behind it?

[Edited on 23-7-2003 by sirius_cm]

Silver from Silver Chloride

ziqquratu - 22-7-2003 at 17:57

Procedure:
- .3g NaOH in 12.5mL water in a 50mL beaker.
- Add .5g powdered AgCl (use mortar and Pestle)
- Add .38g dextrose (normal (racemic) glucose should work here as it is an achiral environment).
- Heat to 70-80*C for 15 min. with stirring
- Filter, wash with water and then acetone.

Another method, similar, uses Zinc powder:
- 5mL of 2M NaOH solution in 20mL water in 100mL beaker
- Add .5g powdered AgCl
- Add .15g Zn powder
- Heat with stirring to 70-80*C (mix turns grey). Continue to heat for 40 min.
- Filter, wash with dilute HCl, then water, then acetone.

There you have it. Using Zn powder gave me a 97.4% yeild, while dextrose gave a respectable 86.8% (and I did get a little sloppy the one time I tried it...).

sirius_cm - 22-7-2003 at 18:48

Quote:

Originally posted by ziqquratu
Procedure:
- .3g NaOH in 12.5mL water in a 50mL beaker.
- Add .5g powdered AgCl (use mortar and Pestle)
- Add .38g dextrose (normal (racemic) glucose should work here as it is an achiral environment).
- Heat to 70-80*C for 15 min. with stirring
- Filter, wash with water and then acetone.

Another method, similar, uses Zinc powder:
- 5mL of 2M NaOH solution in 20mL water in 100mL beaker
- Add .5g powdered AgCl
- Add .15g Zn powder
- Heat with stirring to 70-80*C (mix turns grey). Continue to heat for 40 min.
- Filter, wash with dilute HCl, then water, then acetone.

There you have it. Using Zn powder gave me a 97.4% yeild, while dextrose gave a respectable 86.8% (and I did get a little sloppy the one time I tried it...).

ahh yes, but will it work with mercuric oxide? Any steps taken different than SilverChloride?

ziqquratu - 22-7-2003 at 22:27

To be quite honest, I have no idea if it'll work for mercury salts. I just posted a procedure that I know works for silver chloride using glucose in the hope that it might help out... I think all I'd do to run a test would be to make sure you scale up everything to 2x molar amounts EXCEPT the salt (ie use 1 molar equivalent of Hg salt as compared to the AgCl, and 2 equivalents everything else) as silver, obviously, needs one electron as opposed to mercury needing two. Then give it a go, with a small amount, and see how it works.

chemoleo - 25-8-2003 at 16:34

uhm... I did once the following:
HgS + Fe --> Hg + FeS
standard chemistry. You can find HgS in paint shops, in Germany it goes with the name Zinnoberrot. You extract it with acetone (and leave aside oils/acrylic etc). the idea is to heat HgS with iron powder in a retort, and destill it off under a bunsen flame. worked fine for me. make sure u do it outside tho!! if you wonder where to get a retort from, just check ebay or similar!

vulture - 26-8-2003 at 12:30

Silvercompounds will oxidize aldehyde groups and sugars contain aldehyde groups. This reaction is often used in analytical chemistry.

Nick F - 27-8-2003 at 04:17

Hg2Cl2 or HgCl2 (I forget which the more soluble one is, I think it's HgCl2 since Hg2Cl2 implies a simple molecular structure, rather than ionic, so it is more likely to be a bit covalent and insoluble) in water with Al foil, to make AlCl3 or whatever it is in solution, and metallic mercury amalgamated with the excess Al. Get the metal out, and wash it with dilute HCl, this should remove the rest of the Al. Some mercury will probably also be lost in the HCl washings, I suggest you ppte it as the extremely insoluble sulphide for safe disposal or recovery if there is a significant amount.
I suppose any soluble mercury salt will work. I think this should yield quite pure mercury. I could do with a way to purify mercury, I bought a few hundred g off someone who found it in an abandoned factory, but it was in an open container. It's a bit oxidised and dirty, which is easy to solve, but I don't know how pure it is. I really don't want to try a triple distillation... anyway, that is the method I was thinking about.

madscientist - 11-9-2003 at 12:49

I've found that the result of the decomposition of Hg/Al amalgam in water is Hg(OH)2, not Hg metal.

Mercury salts aren't as precious as they're made out to be. It was easy to prepare HgCl2 by stirring rapidly (with a magnetic stirrer) with an excess of 27.5% H2O2 and 38% HCl, then boiling to remove remaining H2O2 and HCl, and then crystallizing.

Mercury Salts from HgS?

chemoleo - 18-9-2003 at 03:01

Just wondered, is there an easy way of converting HgS (Vermillion, Zinnober, from www.kremer-pigmente.de) to a mercury salt (Like HgCl2) directly, i.e. NOT via the route of metallic mercury and dissolution of that in nitric acid?
HgS is a red pigment, that is extremely unreactive (thus not poisonous), and does not dissolve in acid, water or base (to my knowledge). I imagine a combination of H2SO4/HNO3 might work, though I dont know. Any comments?

Nick F - 20-9-2003 at 06:37

The solubility of HgS is supposedly a few molecules per litre of water, and after a quick search I have not been able to find anything which will dissolve it, but I have only been looking for a few minutes...

Thus I think the only way would be to go to metallic mercury and work from there. Since this will probably require distilation of mercury, you might want to check out other routes...

It might be of interest to people that somewhere on the Hive there is a thread about an OTC mercury compound which can be used for making Al amalgams for reductions etc. A search should find it. IIRC it was not Hg2Cl2, it was something else...

Mercuric salts

the_alchemist - 1-10-2003 at 22:08

What you are doing seems kinda counter productive to me.

I suggest that you keep your mercury salts. They are certainly more useful from a synthetic perspective than the element.

However there is one good way to solve your problem. Create an amalgam and use your salts to break down aluminum, you can use gas line antifreeze as the solvent. It may be hard to recover from the resulting sludge, but the mercury will be returned to the element.

Actually mercury vapor is not quite as bad as people say it is. A friend of mine and I were making HgCl2 and he botched it up, sending a layer of smoke to the top of his garage. We were fine. *cough* *cough* *cough*

Don't take my word for it though, I once gave myself a case of severe ozone poisoning, now THAT will screw with your respiratory system, i swear i oxidized my brain.

[Edited on 2-10-2003 by the_alchemist]