# Can silver purity be tested without dissolving it?



## w0lvez (Feb 13, 2011)

Is there a way to determine if the silver inggot is pure without dissolving all of it? Is there a way to know if the inggot is pure silver and not filled? :?:

I found someone nearby selling silver almost 30% off and up to 45% if bought in large quantity which is almost too good to be true. I bought few gram to test if it's really pure and no copper on it. I dissolved it using nitric acid and the solution was clear. It also don't react with HCL. Is it possible to fill tin with silver?


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## stihl88 (Feb 18, 2011)

just because the solution was clear it doesn't mean the bar was pure, why don't you go ahead and dilute the Silver Nitrate and drop the Silver with a copper rod/bar over night and see how much the resulting silver powder weighs once rinsed and dried. If it weighs the same as the original before you digested it then it's pretty certain that you Silver Nitrate solution is pure.


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## Lino1406 (Feb 24, 2011)

If tin was present you would get white stannic oxide with nitric


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## dtectr (Feb 24, 2011)

Lino1406 said:


> If tin was present you would get white stannic oxide with nitric


http://books.google.com/books?id=cUcsAAAAYAAJ&pg=PA820&lpg=PA820&dq=metastannic+acid&source=bl&ots=TVVB0Ri4fA&sig=bPPnINLg7DS7o85x1DJMyvCciGQ&hl=en&ei=yTAiTYKqNsPflgfutoz9Cw&sa=X&oi=book_result&ct=result&resnum=10&ved=0CDMQ6AEwCTgU#v=onepage&q=metastannic%20acid&f=false 
you'd actually get metastannic acid, mess insoluble in acids or bases. It can be heated to red heat, which converts it to tin/stannic oxide, which is then soluble in concentrated sulfuric or concentrated hydrochloric acid.

Or, after a prolonged boil in concentrated hydrochloric acid, it would be converted to stannic chloride, which is soluble in water. So the multiple rinses in boiling HCl & H2O recommended for clean-up would probably do the trick. To quote lazersteve: "Tin in nitric is problematic."


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