shopsmart
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lead acetate "neutralization"
First post here. Greetings.
What I am looking for is a way through house hold means of making lead acetate less toxic. The fact that it absorbs through the skin makes my skin
crawl.
How it is being made is a cleaning process. Something called "the dip" is created to clean stainless steel baffles from a firearm suppessor. 50%
vinegar to 50% hydrogen peroxide. Lead acetate is the byproduct allong with carbons.
Neutralizing this to a perciipate or something less water soluble would be nice. I have been told table salt might work, but have my doubts.
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j_sum1
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NaCl would work. But Na2CO3 is preferred.
Solubility of lead chloride is 1.08 g/100mL at 20C
Solubility of lead carbonate is 0.00007269 g/100mL at 20C
If I am working with lead salts I mix up both a bucket and a spray bottle of sodium carbonate. Items that have contained lead compounds go in the
bucket. At the end the whole area gets a spray from the spray bottle. Then you can wipe up with a paper towel.
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AJKOER
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A point, tap water containing chloride and CO2, apparently manages to form complexes adding to the increased presence of heavy metals in drinking
water. Apparently, allowing chlorinated water to sit in a Lead pipe for over 4 hours prior to drinking is not recommended.
So take do not trust your well being to observations like "Solubility of lead carbonate is 0.00007269 g/100mL at 20C" in pure water.
I once had the privilege of browsing an online book on the presence of copper in natural waters. I was somewhat surprised on how many possibly
complexes were listed as contributing to soluble copper.
To quote a source, with respect to complexing that occurs with copper, as an example:
"Inorganically bound copper forms complexes primarily with carbonate (60% CuCO3), hydroxide (32% CuOH+ and Cu(OH)2), and 4% free Cu2+ ion (Van Den
Berg 1984)."
Source: "Pesticide Copper (I) Oxide - California Department of Pesticide Regulation - State of California", link: https://www.google.com/url?sa=t&source=web&rct=j&...
With respect to Lead, cited species include PbCl+, PbCl2, PbCl3-, and PbCO3. See "Pitzer model for the speciation of lead chloride and carbonate
complexes in natural waters", by Ryan J. Woosley, link: http://www.sciencedirect.com/science/article/pii/S0304420312...
[Edited on 30-4-2017 by AJKOER]
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unionised
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Lead sulphide is, in principle, even better- but usually less practical.
The precipitated lead carbonate is less of a problem than led acetate, but if it is swallowed it will dissolve in the stomach acid; it's not harmless.
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shopsmart
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It has been 22+ years since I took chemistry. I remember alot, but the numbers will be jack and well you get it, to me. I am looking for a simple
solution to lessen the toxicity of lead acetate. Seeing table salt or baking soda cooked to sodium carbonate makes me smile. Being able to do this
after dipping makes me sweat less. Now drying out the toxic solution, I assume it will be a powder or flake form. Probably keep it somewhat
suspended in water for hazardous waste disposal, so would need to tell them lead chloride or lead carbonate...
I get it about skin absorbtion and swallowing lead differences. Just trying to figure out the lessor of the demons.
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AJKOER
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I would rank the demons as inhalation of Lead fumes/dust, drinking/eating and lastly skin absorption.
Reference: https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_tab...
"Lead (except for certain organic lead compounds not covered by the standard, such as tetraethyl lead) is not absorbed through your skin. When lead is
scattered in the air as a dust, fume or mist it can be inhaled and absorbed through you lungs and upper respiratory tract."
---------------------------------------
I would recommend following the implied path cited below targeting the formation of a basic lead carbonate rather than lead carbonate (which, per my
reference in my thread above, forms complexes), to quote (link: https://www.google.com/url?sa=t&source=web&rct=j&... ):
"Prepared by passing CO2 into a cold dilute solution of lead acetate, or by shaking a suspension of a lead salt less soluble than the carbonate with
ammonium carbonate at a low temperature to avoid formation of basic lead carbonate."
That is, add Lead actetate to room temperature solution of ammonium carbonate. Or, shake warm aqueous Lead acetate in a larger vessel filled with CO2,
or otherwise treat with CO2 (aqueous or gas), as a path to basic lead carbonate (solubility in alkaline solutions, see http://pubs.acs.org/doi/abs/10.1021/ja01393a008 ).
[Edited on 30-4-2017 by AJKOER]
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yobbo II
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Would not some cheap ammonium sulphate from the gargen shop do the trick. You will get lead sulphate which is more insoluble than anything here
(excepting the sulphide). Don't know about the complexes that may form though.
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phlogiston
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precipitating as:
- lead chloride is a very poor choice IMO, it is 'moderately soluble'. It is soluble enough that significant amounts can be recrystallised using water
as the solvent.
- lead carbonate seems a poor choice because even though it is poorly soluble, it could be converted to lead chloride upon ingestion (stomach acid is
mostly HCl).
+1 on precipitating as the sulfide being probably one of the best choices
and precipitating as the sulphate or phosphate perhaps 2nd best options
[Edited on 30-4-2017 by phlogiston]
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"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer |
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unionised
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Assuming this data is right
http://bilbo.chm.uri.edu/CHM112/tables/KspTable.htm
lead carbonate is a lot less soluble than lead sulphate.
However, as has been pointed out, if you add an acid the carbonate will dissolve.
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tsathoggua1
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Sulfate, probably the best bet, or oxides. But the sulfate is stable to strong acid and is piss-poor in terms of solubility, even in sulfuric acid,
its used as one of the two grid types of electrodes in car batteries, in a soup of sulfuric acid, the other grids containing small square blocks of
lead peroxde.
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AJKOER
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Per Wikipedia on PbS (link: https://en.m.wikipedia.org/wiki/Lead(II)_sulfide) to quote:
"Lead(II) sulfide is so insoluble that it is almost nontoxic, but pyrolysis of the material, as in smelting, gives dangerous fumes.[15] Lead sulfide
is insoluble and a stable compound in the pH of blood and so is probably one of the less toxic forms of lead.[16] A large safety risk occurs in the
synthesis of PbS using lead carboxylates, as they are particularly soluble and can cause negative physiological conditions."
I would suggest PbS if made from say adding freshly prepared Aluminum sufide (which reacts with even moist air to release toxic H2S) to aqueous Lead
acetate. An issue is to not generate more H2S in situ then needed. So, estimate the appropriate amount of Al2S3 and add in decreasing doses waiting
till all the H2S is consumed.
Neutralize excess Al2S3 with aqueous chlorine bleach (NaOCl). Perform the exercise with safety gear and in a well ventilated area away from people,
pets,...
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An easier way is forget the H2S based path and just use the NaOCl to create PbO2 (and Cl2 fumes). PbO2 is used as an anode for Lead batteries and is
a strong oxidizer, converting NH3 into nitrate (see Watts at https://books.google.com/books?id=QzrPAAAAMAAJ&pg=PA131&... and also Wikipedia for other comments at https://en.m.wikipedia.org/wiki/Lead_dioxide ).
[Edited on 3-5-2017 by AJKOER]
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Elemental Phosphorus
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I think that lead phosphate would be the best way, since it is extremely insoluble and easier to precipitate than a sulfide, since H2S is toxic and
sulfides are much harder to get than phosphates. 'Triple phosphate' fertilizer contains easily isolated calcium phosphate and the solubility of lead
phosphate is only 0.000014 g/ 100 ml in water.
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