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12AX7
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Photos
Making lead acetate.
First off, the lead oxide. This was created electrolytically with a potassium chlorate solution (I would prefer sodium but I don't have any on
hand) plus other ingredients (KClO3 alone seems to turn basic and plate lead out?), washed and calcined until orangish yellow. PbO is a light yellow
and this is much darker. It's supposed to turn orange/red (Pb3O4) but it hasn't in an hour of good oxidizing heat, any thoughts on that?
Maybe 50-100g here. Haven't weighed it yet.
Tim
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12AX7
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Copper acetate solution. Basic copper carbonate (obtained as posted http://www.sciencemadness.org/talk/viewthread.php?tid=271&am...) dissolved in vinegar. But it isn't very well dissolved, it's quite
turbid and shows no signs of settling. I have heated it with no change. What's going on?
It plates lead quite admirably, but the layer seals instead of flaking off. Does it need agitation, or less pure lead? (Mine's about 99.9%, it
forms crystals on solidification, at least it used to, might be 99.5% after as much use and remelting as it's gone through.)
Tim
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Quince
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Interesting. My copper acetate is not green but deep blue.
\"One of the surest signs of Conrad\'s genius is that women dislike his books.\" --George Orwell
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12AX7
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Had a feeling about that. Does it change color on dilution? (Does mine for that matter, hm better check that.) Addition of Cl ions? Maybe my
carbonate contains residual Cl complexes.
Tim
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Quince
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Your carbonate in there is green as well. It should be blue.
I made the carbonate by mixing a sulfate solution with sodium carbonate (washing soda or roasted baking soda) solution. Sulfate supposedly is sold in
hardware stores, but I've still got some left that I brought over from the Old World a dozen years ago...
\"One of the surest signs of Conrad\'s genius is that women dislike his books.\" --George Orwell
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zoomer
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Quote: | Originally posted by Quince
Your carbonate in there is green as well. It should be blue.
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Metastable basic copper(II) carbonate, Cu3(CO3)2(OH)2, results from the process you describe with room temp materials, and is a light blue in powder
form. However, when oxidized, that material converts to the green stable form, Cu2(CO3)(OH)2, which is what appears to be in the pic in the
referenced thread. Both dissolve nicely in acetic acid to form dark blue copper acetate.
12AX7, that ain't copper acetate. I'm sure you didn't use
heavily chlorinated tap water, right? It's also possible that the green is some form of iron. I've found that to be a common impurity in
"root killer" copper sulfate.
Z
[Edited on 24-6-2005 by zoomer]
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12AX7
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Yeah I'm not concerned about the carbonate, malachite is green after all, and azurite eventually pseudomorphs into malachite. I am concerned
about the acetate though, if it's always blue then something is indeed wrong. I didn't dilute it any, vinegar is dilute enough, so it must
be fixed, in the carbonate.
Could it be something like, uh, (CuCl4)2CO3(OH)2?
Tim
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zoomer
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Or possibly Cu2Cl(OH)3 (which would make it an analogue of atacamite)?
The Cl (or Fe) may have been introduced in the copper sulfate itself, the water used to dissolve it, or by some really cheap vinegar.
Z
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12AX7
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I started with self-made acidic CuCl2 solution, not sulfate. It could certainly be the source of green.
So how about the turbidity?
Tim
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zoomer
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Doh!
Sorry about the sulfate comments, my bad, got my threads mixed up.
Dunno, I'll see if I can reproduce it, that might answer the question about process, anyway.
Z
UPDATE -- I can't seem to repro your result, but that may have everything to do with the brand of shock. I use a local brand by Pool Time.
Z
[Edited on 27-6-2005 by zoomer]
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Cyrus
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Well, I decanted solution from the PbO2 I had made earlier 5 times, filtered it, rinsed it with dH2O, and set it to dry in a dessicator. This took to
long, so I let it dry in the open. Then I put it back in the dessicator, and it dried nicely.
Anyhow, enough water had accumulated in the dessicator to make the CaCl2 liquid, and a week or so later I knocked over the dessicator, spilling the
PbO2 inside and getting CaCl2 all over it.
I really don't feel like purifying it again.
I'm getting a good distilling setup to make some HNO3... so maybe I'll just use lead nitrate for electroplating/making PbO2 anodes.
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Quince
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I was evaporating the water from the lead acetate I prepared by boiling in the microwave. Unfortunately, later in some datasheet for the substance I
read:
Boiling Point: ca. 100C (ca. 212F) Decomposes.
Decomposes? WTF! Does that mean what I've ended up is no good because I boiled it? Looks like whitish crystals to me, with a very slight tint
of blue from remaining unreacted copper acetate, except a mark of brownish green in the center where it got the hottest. Should I assume the white
crystals aren't lead acetate anymore due to heat decomposition?
\"One of the surest signs of Conrad\'s genius is that women dislike his books.\" --George Orwell
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12AX7
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Which reminds me, I've had an (reddish; ferric acetate color?) lead acetate syrup drying over the warm stove (no, no food is being prepared on it
ATM ) for the last two weeks. And uh, yeah... kind of lacking crystallization
here...
Tim
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S.C. Wack
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The 100C figure is probably the point where it begins to lose acetic acid. It probably isn't a good idea to boil it or leave solutions exposed
to air for a long time, it forms basic salts and absorbs CO2.
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Quince
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12AX7, there won't be crystallization until almost all the water is gone if it's very warm. When there's only a little water left, in
my case it formed a very viscous substance, which crystallized upon cooling.
Maybe vacuum drying at 90*C is the way to do this.
I don't think air is a problem, since the procedure for making it directly from vinegar and lead needs the mixture being exposed to the air for
months to a year:
http://www.sas.org/tcs/weeklyIssues_2005/2005-05-20/feature1...
[Edited on 11-7-2005 by Quince]
\"One of the surest signs of Conrad\'s genius is that women dislike his books.\" --George Orwell
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S.C. Wack
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Yes, that process has been known for a very long time - as a preparation of basic lead carbonate "white lead".
The vinegar dissolves the lead, forming acetate which becomes a basic acetate, which absorbs CO2 from the air.
Inorganic Preparations says that the basic acetate doesn't crystallize and somewhat prevents the normal acetate from doing so.
Yes, I have personally dissolved lead with vinegar, and attest that in air the initial acetate crystals on the surface of the lead crumble into
insoluble powder, and clear solutions of acetate turn cloudy and precipitate crap. It takes a while but I assure you that it happens, in a major,
unsubtle way.
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verode
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very easy:
Lead electrodes with conc, sulphuric acid H2SO4 (electrolysis)
Pb + electrolysis ----yields Red Coated PbO2 and very resistent to chlorine you may use later..like electrode
[Edited on 3-8-2005 by verode]
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Fleaker
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IIRC, you can buy lead *monoxide* as litharge for flux/fire assaying for a decent price. I'm sure there's a thermal way to make the monoxide
into dioxide.
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SAM4CH
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Best Solvent!
What is the best solvent that could dissolve lead dioxide (PbO2) powder completely!?
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12AX7
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Hmmm, well it's not water. Molten NaOH? But that forms a compound so it's not acceptable. You might be able to form a liquid solution
with neighboring oxides e.g. Tl2O, In2O3, Sb2O3, etc.
But I don't know why you would specifically want it in liquid state... somehow I get the distinct feeling you either don't know how to
communicate your thoughts or you don't know what the heck you're doing.
Tim
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SAM4CH
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Is this method work for plating lead dioxide? (Electrooxidation of lead acetate in acid solution.14 Lead acetate (100 g) was dissolved in 0.5M acetic
acid solution. A platinum anode and lead cathode were suspended in the solution and a current of density 1.0 mA cm-2 was passed. The deposit was
ground and washed with water.)!!
If it is work for which one PbO2 will plat on +Pt or on -Pb!?
Thanks
Sam
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Nerro
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On a small sidenote I recently dissolved Fe in HAc 80% and H2O2 30% with great succes. The Fe dissolved extremely quickly. Perhaps this is an idea for
lead?
[Edited on 27/11/2005 by Nerro]
#261501 +(11351)- [X]
the \"bishop\" came to our church today
he was a fucken impostor
never once moved diagonally
courtesy of bash
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jpsmith123
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The platinum anode will be plated with PbO2.
What I want to know is, will it be the alpha or beta form of PbO2?
Quote: | Originally posted by SAM4CH
Is this method work for plating lead dioxide? (Electrooxidation of lead acetate in acid solution.14 Lead acetate (100 g) was dissolved in 0.5M acetic
acid solution. A platinum anode and lead cathode were suspended in the solution and a current of density 1.0 mA cm-2 was passed. The deposit was
ground and washed with water.)!!
If it is work for which one PbO2 will plat on +Pt or on -Pb!?
Thanks |
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SAM4CH
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It is beta form..
I want to ask about using graphite aerosol .. is it a good idea to paint any surface with conductive graphite paint.. is it will work to make PbO2
from lead/copper nitrate solution.!!?
[Edited on 28-11-2005 by SAM4CH]
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jpsmith123
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Hello SAM4CH,
I'm wondering, how do you that it is beta form that is deposited form lead acetate/acetic acid solution, do you have a reference dor that?
Also with regard to your graphite coating, I can't say from experience, but as long as it's a conductor and as long as it's compatable
with your plating solution, it should work. (I assume you will make your electrical connection directly to the PbO2).
Regards,
Joe
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