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[*] posted on 21-9-2004 at 19:37


The picture I <i>intended</i> to attach, instead of that horrible closeup:

PbAc2vat1.jpg - 24kB




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[*] posted on 21-9-2004 at 20:45


And here's the result of the very first purification by recrystallization step, 228g of lovely sweet PbAc<SUB>2</SUB>!

I'm boiling more, this is SO fun!!! :D

EDIT: 521g so far...

EDIT2: 890g, and still more than half the liquid left to process...


[Edited on 2004-9-22 by axehandle]

PbAc2_228g.jpg - 29kB




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[*] posted on 24-9-2004 at 05:36


How about heating PbO with NaOH on air? It will oxidize to Na2PbO3, which you then can treat with CO2 or NaHCO3 to liberate PbO2.



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[*] posted on 28-9-2004 at 06:48


Quote:

How about heating PbO with NaOH on air? It will oxidize to Na2PbO3, which you then can treat with CO2 or NaHCO3 to liberate PbO2.

Pb seems unaffected by NaOH regardless of temperature.

On another note, praise the lord for pool chemicals! Only €20 for 2.5kg of Ca(OCl)<SUB>2</SUB>!




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[*] posted on 4-10-2004 at 09:38


Damned, damned, DAMNED!!!

My favorite hobbyist store sold off their entire stock of new, non-acid filled lead accumulators for the equivalent of €6 each and I came too late and they were all gone.... GRRRRAAAAAWWWWRRRR!!!! I could have gotten 150g of pure PbO<SUB>2</SUB> PER BATTERY!!

I should get out more.




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[*] posted on 4-10-2004 at 10:28


Axehandle: for your own sake. Be careful playing with those Pb-salts. Pb has already in extremely low concentrations a strong reducing effect on men's fertility.
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[*] posted on 4-10-2004 at 10:32


Good, it will be a nice complement to my girlfriend's pills.

EDIT: For the humor impaired --- I've washed hands about 500 times while handling the lead compounds...


[Edited on 2004-10-4 by axehandle]




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[*] posted on 4-10-2004 at 10:50


Well well here's some more info on the toxicity of lead salts:

* Mounting evidence suggests that lead poisoning in childhood produces a long-term problem with learning, intelligence, and earning power.

* Adults with lead poisoning have increased incidences of depression, aggressive behavior, and antisocial behavior. Men with lead poisoning tend to have lower sperm counts; women have an increase in miscarriages and smaller babies.

I believe both refer to chronic exposure.

HOWEVER

IVN-RAT LD50 93 mg kg-1 (intravenous)
ORL-RAT LD50: 4665 MG/KG (Oral)

Looks like one has to eat quite a bit (lead acetate in this case) to die at a 50% likelihood.

Re. those dissolution experiments with Copper acetate - the only danger I can see is absorption through skin (apparently possible with the acetate), or inhalation of dusts. I wish I had more info on the rate of skin absorption... how would you measure this anyhow?

Effects are: Fumes, dusts , or vapors may be irritating to the respiratory system, and can result in both acute and chronic overexposure. Symptoms include coughing, shortness of breath, sore throat, and running nose.

On the skin, it may cause irritation with swelling, itching, redness and pain.




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[*] posted on 4-10-2004 at 11:14


Hmm, interesting. I've had no symptoms whatsoever, at least as far as I can tell. Mood swings, yes, but I always have those anyway...

I'm fairly sure my oral exposure has been negligible since I've scrubbed (using a brush) after each and every exposure to the lead compunds, including possible exposures (When unsure, I've washed.).

That leaves skin absorption and inhalation. The only parts of me that's been exposed in ways exceeding the odd small drop of lead acetate solution are my hands, which I've tended to wash within a minute of the exposure. With a brush and detergent.

Exposure is almost impossible to eliminate completely, as I've found -- examples are adjusting a substrate to be plated in acetate solution, getting lead acetate soln. on fingers, etc. I haven't found any way short of using gloves that completely eliminates accidental skin contact...

Inhalation of dust is unlikely, I think, since with the exception of dry PbO<SUB>2</SUB> powder, all my lead compounds have been more or less wet. I'd think the high density of the PbO<SUB>2</SUB> as well as my minimal handling of it (3 short sessions where it contacted my fingers) help here?

Fumes are a bit unnerving, but does Pb(Ac)<SUB>2</SUB> really get into the steam in more than a negligible amount when boiling the aquous solution?

The Merck says lead acetate has historically been used as an astringent. On the other hand, mercury salts have been used as cure for syphilis, and leeches have been used against the flu...




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[*] posted on 4-10-2004 at 11:32


I don't think any lead salts except straight organics (with a carbon-lead bond) are absorbable though the skin to an appreciable extent. Additionally calcium uptake is preferred over lead for incorporation into the skeletal matter and muscles. As long as you are not deficient in this, you should at least have an edge, take a calcium supplement or drink lots of milk :D



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[*] posted on 2-12-2004 at 21:18
Plastic


Still looking for that EXCELLENT plastic substrate. No winners so far ! Everything likes
to cook off with my battery charger. SONOFABITCH ! Bear in mind that I have LOTS
of perchlorate for the moment Just wanted to experiment with different substrates.
As for lead compounds causing psychological problems, no problems there. I'M ALREADY
INSANE ! MWUHAHAHAHA ! God damn it, I just want something that works for a relatively
long time !




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[*] posted on 25-2-2005 at 20:05


I'm interested in Pb3O4 instead. What would you experts recommend to get from Pb to Pb3O4?



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[*] posted on 7-6-2005 at 16:03


This is an old topic, but I want to check a few things.
Here are the reactions. (are they correct?)

CuCO3 + 2HC2H3O2 -> Cu(C2H3O2)2 + CO2 + H2O

~

Cu(C2H3O2)2 + Pb -> Pb(C2H3O2)2 + Cu

~

Pb(C2H3O2)2 + 2NaOH -> Pb(OH)2 + 2NaC2H3O2

~

Pb(OH)2 + NaOCl -> PbO2 + NaCl +H2O

~

Also, about the procedure; I took 15 g of CuCO3 and added a lot (perhaps a liter) of 5% acetic acid. (plain vinegar) I'm not sure that this concentration of acid is enough to dissolve the CuCO3 properly. It dissolved very slowly, making almost no noticable bubbles. After a few days, there was plenty of CuCO3 left at the bottom, but there also seemed to be plenty of acetic acid. (it still smelled very strongly) How long ought this to take?

Also, when I added lead turnings, small amounts of white powder quickly formed. I don't think it was lead acetate, because its solubility is about 60g/100 ml of water.

Perhaps it was a double salt of copper hydroxide/ acetate, as chemoleo mentioned much earlier in this thread.

Anyways, the lead acetate will be mixed with NaOH to form lead hydroxide- this should precipitate, but should redissolve with extra hydroxide added. Then I'll use plain old bleach to make the PbO2. As far as I can see, exact amounts aren't needed in these reactions.

Yes, I'm being very careful with lead.

And the PbO2 will be used to smear on ceramic anodes. (I'll also dry soaking the anodes with lead acetate and then putting them in bleach, as axehandle did.)




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[*] posted on 7-6-2005 at 16:26


Try dissolving it in HCl instead. I'd bet a euro or two :D that this will work. Acetic acid may just not be aggressive enough, CuCO3 is fairly stable and is used in paints, hence i assume if somewhat crystallised, or hydroxy carbonates (double salt) it is more active. It won't help you directly with your problem, but at least you know that you got the Cu carbonate all right. Well you could always preciptate from the CuCl2 solution again, with carbonate or hydroxide, and dissolve the now *activated* hydroxide or carbonate in HAc. Bit of a waste of reagents, but they are all cheap :)

Did you try boiling the carbonate in HAc?
Really though you ought to use pure HAc (obtainable here as 25% concentrate), you are introducing all sorts of impurities here, including other organic acids!


On a separate note, I remember that CuO wouldnt dissolve that greatly in HAc, and NiO takes a long time in strong HNO3 to dissolve. I reckon it's just due to the relative chemical stability of the (oxy) carbonates.

Re. the white powder - it could be Cu(1+).
It can form from Cu(2+) + Cu --> 2 Cu(1+). It should disappear w. time. Otherwise it's impurities, in either the lead or your reagents, or, as you say, some hydroxy-acetate precipitate. My commercial batch is insoluble too :( - which is a big pain btw, pure lead acetate crystals, as nice and heave as they are, become first turbid, then white on the surface. I couldnt find a to keep them shiny.


PS For conventions sake, acetic acid is CH3COOH - carboxylic acids R-COOH in general... makes it easier to read :P


[Edited on 8-6-2005 by chemoleo]




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[*] posted on 7-6-2005 at 16:41


Cyrus: When I performed this procedure, I used 24% HAc, and I had to stir the mix of HAc and CuCO<SUB>3</SUB> for quite some time for all of the carbonate to be converted to acetate / dissolve. Lots of CO<SUB>2</SUB> was produced. Perhaps it's your low HAc concentration?

Also, you don't have to basify the Pb(Ac)<SUB>2</SUB> solution with NaOH prior to mixing it with bleach -- the bleach contains more than enough NaOH to do the job. The same seemed to be the case with bleaching powder (Ca(OCl)<SUB>2</SUB>;), although the base there obviously is Ca(OH)<SUB>2</SUB>.




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[*] posted on 7-6-2005 at 22:43


I found lead oxide, lead acetate, and other lead salts here:
http://stores.ebay.com/CHEMSAVERS-INC/
You could ask the seller if he'd consider shipping to you. I need acetate myself, so I'm hoping he'll send me some to Canada.

BTW, is there a route from lead acetate to lead nitrate?

[Edited on 8-6-2005 by Quince]




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[*] posted on 8-6-2005 at 02:25


You could try this method: Precipitate the lead with a base, wash away the soluble byproducts, then redissolve your precipitate in nitric acid.
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[*] posted on 8-6-2005 at 16:39


Chemoleo, I probably should have used nice conc. acetic acid, but I don't have any. I'll have to get some, any suggestions?

I added a whole bunch of lead, and after 2 days the blue color is almost all gone. (I stirred a few times a day) But there is now a lot of very fine white powder floating around when I stir it. (The pH is between 3 and 4) I guess I'll just wait around and see if it goes away, or I could always filter it out.

Now here's a dumb question; when I've got my lead acetate solution is there any particularly safe way to turn that into lead acetate crystals. (I don't like the idea of boiling it, as when I boiled sodium acetate I could really smell the sodium acetate coming off) :(
Slow evaporation?




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[*] posted on 8-6-2005 at 17:49


I boiled in about 10dm<SUP>3</SUP> of Pb(Ac)<SUB>2</SUB> solution, and I'm alive...

I boiled it down to a syrupy fluid which I poured into several paper plates (the kind you eat from). I then placed the paper plates on ice, whereas the Pb(Ac)<SUB>2</SUB> crystallized out. Then I dumped the crystals + remaining fluid (discolored by impurities) into a funnel equipped with a coffee filter; the discolored fluid went through the funnel, the Pb(Ac)<SUB>2</SUB> crystals (big lumps of them actually) stayed in it. The result looked pretty pure, and the procedure is repeatable...

Someone probably has something not so nice to say about my lab skills, but my method worked... :)

[Edited on 2005-6-9 by axehandle]

[Edited on 2005-6-9 by axehandle]




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[*] posted on 8-6-2005 at 17:58


Axehandle, not sure if you're still interested in electrolytic PbO2, but I found an article that is interesting:

http://www.geocities.com/CapeCanaveral/Campus/5361/chlorate/...

Maybe you guys have already seen this?
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[*] posted on 8-6-2005 at 19:43
Heh


"I boiled in about 10dm3 of Pb(Ac)2 solution, and I'm alive... "

Yeah, but I want to be alive and SANE...:P

I was thinking, perhaps it's not even necessary to get lead acetate crystals. One could get PbO2 just by adding bleach. As for using the lead acetate "as is" for electroplating, I don't know if the impurities would hurt anything though.

edit-
~
Impurities in the bath, such as iron or cobalt compounds, can drastically reduce the strength, density, and surface smoothness of lead dioxide deposits
~

This was taken from the link right above this post.


[Edited on 9-6-2005 by Cyrus]




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[*] posted on 9-6-2005 at 01:20


Quote:

I was thinking, perhaps it's not even necessary to get lead acetate crystals. One could get PbO2 just by adding bleach. As for using the lead acetate "as is" for electroplating, I don't know if the impurities would hurt anything though.


If you want to be sane, note that bleach + acid = chlorine gas.




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[*] posted on 9-6-2005 at 02:30


This shouldn’t be a problem. The reaction between bleach and acetic acid is very slow and gives almost no chlorine.
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[*] posted on 9-6-2005 at 14:31


Also, the NaOH in the bleach should neutralize the acid. When I took about 0.5 of a jam jar's worth of lead acetate solution and added bleach, it turned a clear light green at first, then yellow, then red, and all of a sudden (within 1/5 of a second, perhaps) an orangish brown precipitate filled the entire solution. I added a bit more bleach, and it kept on getting darker brown for a few minutes. By now it has all settled to the bottom of the container, which smells very much like bleach. Now it's just a matter of decanting off the solution over and over. I wonder what I'll do with the solution (I'm collecting everything I know has even tiny amounts of lead (especially soluble forms) to dispose of properly)- it shouldn't contain any soluble lead salts, but still, to be safe....



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[*] posted on 12-6-2005 at 00:44


Quote:
Originally posted by chemoleo
Well here it goes... the dissolution of lead metal with cheap OTC materials. I copied parts over of what I posted at E&W already:

Quote:

A while back I managed to solubilse a kilogram of lead with a neat little method. I didnt want to waste HNO3 for the dissolution, neither NH4NO3 etc. Neither did I have any existing lead salts, or lead oxide.

But I did have about 20 kg of solid lead metal, plus 10 kg of copper sulphate (CuSO4), obtained from a gardeners store.


I got it to work as follows:

1. Calcium carbonate is easily obtained, I neutralised a known amount with acetic acid (conc. vinegar), yielding a solution of calcium acetate.

2. I dissolved an equimolar amount of Copper sulphate CuSO4, and added to it the stoichiometric amount of calcium acetate. What you get is copper acetate and calcium sulphate

3. THe precipitating calcium sulphate is filtered off, then the filtrate is cooled to precipitate more CaSO4, and filtered off again. One is left with a fairly clean solution of copper acetate, which has a lovely dark green colour and tends to crystallise at the surface of the the liquid.

4. This is probably the longest step - to the solution of copper acetate, one adds a large excess of solid lead metal! the finer the lead pieces, the better (faster). Over the course of a week or two, the copper acetate colour (dark green) slowly disappears, and becomes completely colourless. What happened meanwhile is that solid copper deposited as thin sheaths on the solid lead. I found no stirring is needed during those two weeks, the copper deposited anyway.

5. The solid copper is scraped off the remaining lead, the lead pieces are taken out, and the solution is filtered once again to remove copper pieces and any more CaSO4

6. One is left with a clear solution of lead acetate. Made from 100% over the counter materials. Slow evaporation of the water in the solution leads to LARGE crystals of lead acetate, which are very heavy and slowly become milky/powdery on the surface at air!


Quote:

Follo-up: When the Ca acetate started reacting over the course of a week or two, I noticed that an insoluble yellowish substance accumulated at the side of the reaction vessel.
Thinking, oh, this must be because the HAc evaporates (which is, as I found out later, because the double salt of the hydroxid/acetate forms, plus possibly PbO), I added 500 ml of 20% HAc to the 5 litres in the reaction vessel - and promptly, the yellowish stuff disappeared, and it was a clear green (later clear altogehter) solution again.
From that point onwards, I always made sure I keep the solution acidic, with excess acetic acid!


Well axehandle, there is nothing stopping you! It's a nice and satisfying experiment. I really really hope you do not claim that you can't find lead sheets/airgun bullets/fishingweights/lead solder anywhere in Sweden! :D


PS H2O2 does not necessarily work, I think Bromic only thought it might work too!

[Edited on 28-4-2004 by chemoleo]




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