Clonejeffie
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Disolving and purifying silver
I want to purify silver from a silver teacup I found in my garage there were no visible markings on it so I tried heating it up with a torch and it
looked like another piece of silver i had when I heated it up. I was thinking of dissolving it in some sort of acid and then using electrolosis to
precipitate silver metal. What acids could I use? Would 5% vinegar mixed 50/50 with 3% hydrogen peroxide work?
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anewsoul
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Using that concentration of vinegar and peroxide would probably take forever (if it works but I'm not certain). Nitric acid is usually used for
dissolving silver. Also don't forget that silver salts usually decompose into silver when exposed to light.
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NitratedKittens
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No, I think the only acid which can dissolve elemental silver is nitric acid, once dissolved you could recrystallise the silver nitrate then,
precipitate with copper metal then melt into a bead with a crucible with borax as flux in it
Basket of kittens for you ........BOOM
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Clonejeffie
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I have used that mix before to dissolve silver plating and It worked fine the solution turned bluish-green. What could it have produced and could I
electrolyse it to get pure silver metal.
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Texium
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The blue green would be from copper alloyed with the silver. Silver salts are colorless.
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Texium
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Thread Moved
22-2-2017 at 11:20 |
Clonejeffie
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Nitratedkitten I don't have money to buy acid and I want to use something safer but I do have kno3 could that be used to make nitric acid?
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Clonejeffie
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Can hydrogen peroxide oxidize silver under acidic conditions?
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Clonejeffie
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Anewsoul with that mixture i left it to dissolve for a few days within an hour or so it turned a slight blue color that darkened over a few days of
reacting
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diddi
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use hot nitric acid
Beginning construction of periodic table display
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Melgar
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Depends very much on the acid, since it has to form a soluble silver salt. Otherwise, an insoluble silver salt will coat the metal, preventing it
from going into solution.
For dissolving silver, the best is dilute nitric acid and hydrogen peroxide; the hydrogen peroxide reoxidizes the NOx vapors back to nitric acid so
you don't have all those nasty brown fumes. Also, less wasted acid.
You can use KNO3 to make nitric acid, provided you have a mineral acid with a high boiling point (sulfuric and phosphoric are the only two I've heard
being used) and you can distill acid out of a mixture. Dilute mineral acids should work too, since you only need dilute nitric acid to dissolve
silver.
Alternatively, you can try mixing acetic acid, potassium nitrate, and hydrogen peroxide and see where that gets you. That mixture would have small
amounts of nitric acid present at any given time, which would make it faster than without the nitrate, though not as fast as nitric acid alone. Try
an experiment, and see whether adding a nitrate salt to acetic acid and peroxide makes the silver dissolve faster? No matter your findings, we'd
appreciate hearing back regarding what you've learned!
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Clonejeffie
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Melgar Thanks for the help. I tried adding 4g KNO3 powder with 50ml of 3% hydrogen peroxide and 60ml of 5% vinegar and the solution turned slightly
brown/red. I used silver test solution which showed that the silver pieces were around 80% purity. The solution is in a hot water bath(glass jar) with
an evaporating dish covering it so the heat stays in longer. Ill check back in an hour or two to see what if anything happens.
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symboom
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Might as well post an update somewhere I dont like to start new posts
Attemped to desolve silver in perchloric acid
Added the silver to ammonium perchlorate and sulfuric acid mix no reaction noted no bubbling observed
Waiting for it to desolve 8 gram silver bar
Citric acid and sodium citrate forms nitrogen dioxide
[Edited on 24-2-2017 by symboom]
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