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The_Davster
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A while back I was able to dissolve lead in vinigar by adding a dash of 35% peroxide. However after the reaction there was some solid white lead
compound on the bottom of the beaker that had to be removed before further use.
[Edited on 14-11-2005 by rogue chemist]
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Pommie
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I just tried the Ca(NO3)2 + CuSO4 combo.
I dissolved 118g Ca(NO3)2 in 200mL water and 125g CuSO4 in 200mL. They both dissolved completely as expected. I then mixed them. I instantly got what
I can only describe as about 600mL of ice cream consistency gunk. To try and recover something, I topped it up to 1L and have left it to settle.
It's now about 25% clear liquid which I can decant. Guess I'll decant and wash a few times to get my copper nitrate. At least I've
learnt something - reactions that have CaSO4 as a product need LOTS of water or should be avoided.
Anyone any suggestions beside sticking it in the spin dryer?
Mike.
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garage chemist
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Vacuum filter it through a sintered glass filter. That's what I used for the CaBr2 + H2SO4 reaction to get dilute aqueous HBr.
This also forms "ice cream" like you described, but on scooping this onto the glass filter and applying vacuum, the voluminous precipitate
drastically shrinked and I got a good yield of HBr, only minimal washing of the CaSO4 being necessary.
Boiling the liquid with the precipitate also helps to improve the filterability (I made up this word). It coagulates the fine CaSO4 particles into
larger ones.
[Edited on 14-11-2005 by garage chemist]
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mrjeffy321
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So how long is it expected to take for the lead to react with the Calcium Acetate? I expected a few days atleast. The best I can come up with for
lead is melted chunks that I can pound out flatter and thinner to make more surface area.
I never through of suspending the lead in the solution, I will try that too.
| Quote: | | A while back I was able to dissolve lead in vinigar by adding a dash of 35% peroxide. However after the reaction there was some solid white lead
compound on the bottom of the beaker that had to be removed before further use. |
With the lead I have sitting in the acetic acid right now, there is a very small amount of white powder sitting at the bottom (perhaps the same
thingas what your talking about), but I never added any H2O2 to m batch.
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chemoleo
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You mean copper acetate, not calcium acetate.
The reaction can take up to several weeks, depending on the surface area of the lead. Poor molten lead into water, that will give you small pieces
(high SA).
Have an excess of lead too.
The end of the reaction is easily told: The CuAc2 colour disappears. Also add some extra HAc to keep the solution acidic.
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mrjeffy321
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| Quote: | Originally posted by chemoleo
You mean copper acetate, not calcium acetate. |
Yes, of course, I mean Copper Acetate reacting with lead.
I will try that idea of pouring liquid lead into water.
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mrjeffy321
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I just got done with phase 1 of the experiment and I have a problem.
I reacted all the Calcium Carbonate with the Acetic acid giving me a bubbly white mixture. I heated it up for a while in the stove, but didnt boil
it. I then took it and dumped it in a bucket whcih I then inten added the Copper Sulfate solution. Nothing appears to have happened. I am suppose
to get a very thick mixture after the Calcium Sulfate forms, "Like Ice Cream" as one person puts it, I didnt not, mines was still very
watery. I am also suppose to be forming a dark green solutuion of Copper Acetate....I did not, I still have a dark blue solution, just like the
copper Sulfate was before. I do seem to have a white percipitate that when I stir up the mixture, it becomes light blue, but other than that, I fear
that I have done something wrong, my results are not like those described.
If you want to check my math on how much of everything I was suppose to have added,
I reacted about 100 grams of Calcuim Carbonare with about 2.4 Liters of 5% vinegar. Seperately I prepared about a 1 Liter solution of Copper Sulfate
by dissolving about 250 grams of Copper (II) Sulfate Pentahydrate crystals in water.
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Pommie
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| Quote: | Originally posted by mrjeffy321
Nothing appears to have happened. I am suppose to get a very thick mixture after the Calcium Sulfate forms, "Like Ice Cream" as one person
puts it, I didnt not, mines was still very watery.
If you want to check my math on how much of everything I was suppose to have added,
I reacted about 100 grams of Calcuim Carbonare with about 2.4 Liters of 5% vinegar. Seperately I prepared about a 1 Liter solution of Copper Sulfate
by dissolving about 250 grams of Copper (II) Sulfate Pentahydrate crystals in water. |
You have got much more water than I had. Your light blue colour when stirred is the precipate. You have 1 mole of each substance in 3.5L - I had 0.5
mole of each in 0.4L.
When your precipitate settles, you should end up with about a Litre of the stuff.
Mike.
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mrjeffy321
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But that wouldnt change the color would it?
I let it settle completely, then decants and filtered off the liquid and I was left with a light blue filtrate. The liquid was a deep blue.
I then boiled some of the liquid down for a while until I began to notice a smell and stopped. At this point, I boiled away about 700 to 800 mL. I
had a pale green solid that settled to the bottom and a lighter blue solution, not nearly as deep as before but still very blue. The to my horror, I
examined the pan I boiled it in....there is a dark green substance caked onto the bottom. I have scrubbed and scrubbed and put a lot of efort into
cleaning it, but I have made little progress.
Right now I am cooling the liquid I just boiled to see if I can percipitate out anything else and desperately trying to clean by pan.
EDIT:
OK, I cooled the remaining liquid to its freezing point (where it was just begining to solidify), and I got no additional percipitate. After letting
the solution settle all night, I got a small amount of pale green stuff at the bottom. The liquid above is the same deep blue as it was before I
boiled it. So there is something green, but there isnt very much of it, and it isnt in solution.
I had to resort to use very corse sand paper to clean the bottom of the pan. The green stuff that is caked on, it not easy to get off, but it would
appear to be the same stuff that is settling to the bottom of my blue solution.
So I must have done something wrong, but what. My only guess is that it has something to due with either the purity of my calcium Carbonate, or the
fact that I had very diute solutions of everything, possible preventing the reaction from taking place.
[Edited on 16-11-2005 by mrjeffy321]
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SAM4CH
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Graphite Aerosol!??
Can I use Graphite Aerosol instead of using graphite rods, in aerosol we can paint any surface and it will be conduct electrisity and then I can coat
it with PbO2 using lead/copper nitrate solution!!?
Please see this
http://www.a-m.de/englisch/produkte/spray-gs.htm
Sam
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mrjeffy321
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I dont see any reason why not, other than if the layer is too thin, too much graphite might errode before a good coating of PbO2 gets on the
electrode. It is definatly something to try I think.
Also, it would seem my previous method of making lead acetate has failed.
I am trying another method now,
I am making some Lead Chloride by reacting metalic lead with Hydrochloric acid (the reaction is going on right now). The I will take that and react
it with Sodium Carbonate (I will substiture NaHCO3), to make Lead Carbonate. The I will react the Lead Carbonate with acetic acic to produce Lead
Acetate.
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neutrino
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That sounds like it will be dificult given the low solubility of PbCl<sub>2</sub>.
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12AX7
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Nah. Reactivity is less though. You need to boil it (reflux preferred since HCl is nasty) to dissolve it reasonably fast. As a plus, you can pour
off the liquor, cool it and PbCl2 drops out nearly quantitatively (though I forget how much PbCl2 is soluble in cold HCl).
Tim
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neutrino
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Sorry, I was referring to the carbonate step. Neither the product nor reactant are very soluble.
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chemoleo
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Oh dear... axehandle himself did that. Lead dissolves VERY badly in HCl. Mainly due to the bad solubility. I don't think he ever got significant
yields out of that.
mrjeffy - by the sound of it, your first step went already wrong.
Calcium acetate is SOLUBLE. When you neutralise CaCO3 with HAc, you should be left with a CLEAR solution, not a white bubbly mixture. Only then you
add the CuSO4, which is a CLEAR blue solution.
When mixed, the solution turns dark green, and the CaSO4 precipitate forms, which can be filtered off.
If you didn't even get to that stage, it's no point putting lead into it.
Use 25% vinegar concentrte, that's what I used at the time, and clean powdery CaCO3. REmember you are left with a clear solution, before you even
put the CuSO4 in.
Never Stop to Begin, and Never Begin to Stop...
Tolerance is good. But not with the intolerant! (Wilhelm Busch)
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mrjeffy321
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I got the Carbonate idea from this site,
http://www.geocities.com/CapeCanaveral/Campus/5361/chlorate/...
The idea is to get solid Lead Chloride and solid Sodium Carbonate and react them together in boiling water.
As it says,
| Quote: |
This should produce pretty pure PbCl2. Now, weigh the PbCl2 (You do not have to dry it first). Place the PbCl2 in a container and to every 100 grams
of PbCl2 add 50 grams of sodium carbonate. Add 300 ml's of water (or more if it doesn't seem enough) and boil the mixture for about 15
minutes. Stir well. Then, let the PbCO3 that has formed settle and decant the liquid. Add 300 ml's of fresh water and boil again. Let settle,
decant and repeat one more time. This should remove any Na2CO3 that is left in the PbCO3.(lead carbonate)
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My Calcium Carbonate source is of questionable purity. I am using a cleaning product called, "Bon ami", Which is suppose to be plain CaCO3
without any other "extras" other cleansers put in. The reaction was kind of slow (very slow by a comparison to NaHCO3 and vinegar), and
possible left a white color to it since there was a suspension of unreacted/undissolved particles?
Whatever happened, no reaction seemed to occur when I mixted it with my dark blue, clear, CuSO4 solution (except the formation of a mysterious green
powder) and I did not continue on after that step.
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12AX7
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Geez, go out to the garden with a dropper of acid and look for rocks that fizzle when you drip acid on them. More than likely these will be either
limestone or dolomite.
In the case of dolomite, you'd want to react with sulfuric acid, wash the precipitate (the solution contains magnesium sulfate and the
precipitate is calcium sulfate), add sodium bicarbonate (to give calcium carbonate) until it stops bubbling, wash the precipitate (removing excess
sodium sulfate and carbonate), then use this. Should be, oh I'd guess 99% or better calcium carbonate, aka whiting.
In the case of limestone, grind it and use as-is.
For the most part you can ignore the magnesium and iron impurities, so either may be suitable to start with anyway.
Tim
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