aurora369
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Silver sulfate
I've acquired some silver sulfate for free. It's a silver salt, so it's a valuable grab anyway. But I wonder what can I do with it.
Is there an easy way to convert it to silver nitrate? I've come up with a way.
1. Make the soluble complex diamminosilver sulfate;
2. Swap the sulfate ion for nitrate by adding barium nitrate to the solution;
3. Evaporate and crystallize.
Is there a simpler way?
Another question on this salt. Can I use it for the silver mirror reaction? Can a solution of diamminosilver sulfate alkalified with KOH be a
substitute for the solution of diamminosilver hydroxide?
Edit(woelen): User aurora369 was the same as ave369
[Edited on 16-1-17 by woelen]
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unionised
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Silver sulphate is just about soluble in water. Silver carbonate is much less so.
It should be possible to convert the sulphate to the carbonate by treating it with an excess of a solution of sodium carbonate.
You can then dissolve the carbonate in dilute nitric acid to get silver nitrate.
Washing soda is a lot cheaper than barium nitrate.
I can't see any reason why the sulphate shouldn't work for making silver mirrors with.
Why not try it?
(The usual warnings about silver ammine solutions and their explosive nature will still apply here).
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JJay
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I think you could dissolve it in water with, say, potassium nitrate and precipitate the silver with copper or aluminum. I don't think silver sulfate
is very soluble, so this could require a lot of water and will probably be pretty slow for this sort of reaction. Of course, then you'd need to
dissolve the precipitate in nitric acid.
[Edited on 16-1-2017 by JJay]
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ave369
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What I forgot to mention that the silver sulfate is old and has some elemental silver in it anyway. It is gray in color.
I also have a jar of silver nitrate which is also old and gray. I plan to regenerate it by making a slurry of it with nitric acid, which will
re-convert all elemental silver back to silver nitrate, and then drying this slurry. Will it work?
BTW, what is the maximum concentration of nitric acid usable for this? I'm aware that very concentrated fuming NA is slow to react with metals, while
65% NA is quick. How does fuming NA react with very fine particles of silver? I want to minimize the water content in the slurry.
By the way, the silver mirror experiment with the sulfate was a success.
[Edited on 16-1-2017 by ave369]
[Edited on 16-1-2017 by ave369]
Smells like ammonia....
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Fleaker
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I used to take silver sulfate (and chloride too) by the kilogram and mix with dilute (5-10%) sulfuric acid and some iron nails and cement it into
silver sponge. I would do this in a cement mixer and mix well well for 5 hours, filter and rinse well until no salts are in the filtrate and then
rinse with a borax/carbonate solution and melt the silver. In a 3 cubic foot mixer, I could do several thousand ounces in a day.
Also, you can do the great method unionised recommended and make silver carbonate or silver oxide out of it, filter that free of sulfate, and then
dissolve in dilute nitric acid (no fumes should be produced).
The silver sponge can then be redissolved in a 5% excess of 30% nitric acid (don't use RFNA), filtered, and you can add your old silver nitrate to the
nitrate made from the cemented silver and evaporate down to perhaps 1000 g/L Ag basis. Then slowly add the concentrated nitric and filter out the pure
silver nitrate crystals.
Neither flask nor beaker.
"Kid, you don't even know just what you don't know. "
--The Dark Lord Sauron
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ave369
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Thanks.
Smells like ammonia....
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