Sciencemadness Discussion Board

AgNO3 Yields/ synthesis

prometheus1970 - 26-5-2011 at 22:22

I'm looking to make silver nitrate for the purpose of making Ag double salt (Ag2C2/AgNO3). What I have is sterling silver, rather than .999%. I read somewhere that if your solution contains copper, the acetylene gas won't react with the copper ions and you still get the Ag double salt you desire. My question is how much AgNO3 will I get per gram of sterling silver I dissolve in 70% HNO3. I thank you for your assistance in this matter. Also is the info correct about copper ions not interfering with the synthesis of the double salt?




[Edited on 5-27-2011 by prometheus1970]

LanthanumK - 27-5-2011 at 03:04

.999% silver is less pure than 1%, by the way. :P

1.46 grams of silver nitrate per gram of sterling silver is produced according to my calculations. The starting point is .925 grams of silver, which is the amount of silver in one gram of sterling silver.

Ag purification

dabeak - 28-5-2011 at 22:53

You can separate the Ag from the Cu by precipitation of AgCl. Boil it to aid in filtration and wash it well. The AgCl will then dissolve in ammonia and the Ag is reduced via electrolysis.

I make a Cu wire frame tree and grow fine lacy Ag from the nitrate on it for a Christmas tree. So I use this method to recycle the Ag and separate it from the Cu. For this application I use Zn to reduce the Ag from the ammonia. If you have a lot of Ag and use too much Zn it will go runaway, still some Ag on the ceiling there.

prometheus1970 - 29-5-2011 at 09:57

Back to my original question, do I need to remove the Cu from the AgNO3? Or will the presence of Cu not interfere with the reaction? (the reaction occuring when I bubble acetylene gas through the AgNO3 soln. to make Ag DS)

[Edited on 5-29-2011 by prometheus1970]

symboom - 29-5-2011 at 13:57

Quote: Originally posted by prometheus1970  
Back to my original question, do I need to remove the Cu from the AgNO3? Or will the presence of Cu not interfere with the reaction? (the reaction occuring when I bubble acetylene gas through the AgNO3 soln. to make Ag DS)

[Edited on 5-29-2011 by prometheus1970]


remove the copper beccause they are both in solution it will react with the more reactive salt first
ie copper metal will displace silver nitrate into silver metal crystals

prometheus1970 - 29-5-2011 at 14:32

Thanks, everyone!

KemiRockarFett - 4-6-2011 at 03:55

Quote: Originally posted by dabeak  
You can separate the Ag from the Cu by precipitation of AgCl. Boil it to aid in filtration and wash it well. The AgCl will then dissolve in ammonia and the Ag is reduced via electrolysis.

I make a Cu wire frame tree and grow fine lacy Ag from the nitrate on it for a Christmas tree. So I use this method to recycle the Ag and separate it from the Cu. For this application I use Zn to reduce the Ag from the ammonia. If you have a lot of Ag and use too much Zn it will go runaway, still some Ag on the ceiling there.


Or take the silver/copper nitrate solution and place a copper bar in it to get silver as metal. This silver could be solved in nitric again and the most of the coppper should be gone.
Check for copper ions by adding ammonia and see if you got a deep blue coluor change. If so, reapat.

prometheus1970 - 8-6-2011 at 07:03

I have since decided that it's much more practical just to buy the AgNO3. Thanks again for the help.

cyanureeves - 8-6-2011 at 10:55

if you have decided then you've decided but i bought silver nitrate years ago and it just sits in a bottle in my closet because it is so easy easy easy to make by either method described above. it is the only thing i knew how to do before i started doing stuff i learned here.i still make it sometimes now because sterling keeps popping up mixed and passed as costume jewelry.to see sterling go to copper nitrate and silver nitrate and both in different forms is awesome, then to separate them and to witness a displacement of zinc or copper with silver right before your eyes is the coolest thing i've seen. its like metals fight each other for certain acids. i will never have to buy silver nitrate again.

LanthanumK - 8-6-2011 at 14:09

You may not always want to buy chemicals; the production of chemicals is almost as interesting as the reactions that they undergo.

prometheus1970 - 8-6-2011 at 15:50

Yes, but silver is so expensive right now and most of the time when I find it for sale, it's in the form of some even more valuable coin, boullion, memorabilia, etc.

dabeak - 8-6-2011 at 16:29

You can buy scrap silver and purify it too. A lot of silver used for film (mostly xray film now) is recovered with small electrowinning cells. It's called electrolytic silver and it is quite pure as is. Any local business that buys old gold and silver jewlery might also be a source a bit below the market price.

prometheus1970 - 8-6-2011 at 19:31

I'll keep that in mind. Last time I made a pretty honker size batch of AgDS (9 grams) I probably won't need any for awhile...

LanthanumK - 9-6-2011 at 03:08

Trying making smaller batches of expensive compounds like silver salts and using smaller amounts in experiments; that will save money and be easier to dispose of.

quicksilver - 9-6-2011 at 05:05

Personally speaking I made quite a bit of AgNO3 and I won't bother with anything less than high quality silver. It's simply too much trouble. I stick with 99%. I've tried Sterling and it's simply too problematic....some even has copper. The fastest is pure wire cut in small bits as it dissolves in acid very quickly and the whole synthesis can be completed in a few minutes.

prometheus1970 - 9-6-2011 at 05:34

The reason I made a larger batch was that every time I do this synth, I end up with some spillage at some point and AgNO3 stains the wicked shit out of everything. By making all I'd need for awhile at once I reduced the amount of stains, wasted reagent. I figured out how to eliminate the biggest part of my spillage problem. I had been grinding up the AgNO3 crystals to make them more soluble, but did some research to find that silver nitrate is absurdly soluble in water. If the water is hot you can dissolve a kilo in only 80 grams of water. So this last time I skipped the coffee grinder step (it was transfering the AgNO3 powder from the grinder to the reaction vessel where I had most of my problem) this last synth was virtually mess free and I have enough DS to make enough caps to last me quite a long time.

[Edited on 6-9-2011 by prometheus1970]

quicksilver - 10-6-2011 at 04:33

Oh don't get me wrong, I'm all for making one synthesis and being done with it: I just always go with the purest components and efficient means possible at the time.
IF you can find one, many DIY jewelry making outlets sell 99% Ag wire; you cost is generally high about 50% greater than the cost of the silver per se' but the form makes for fantastic efficiency (thin wire) as when they are cut to 1 CM length - they dissolve right up in your acid and using a hot water bath you're on your way in a few minutes.

I don't remember the yield but it's good.

[Edited on 10-6-2011 by quicksilver]

prometheus1970 - 10-6-2011 at 06:14

I've looked at the wire before and the prices are reasonable, I just got kind of confused about the grades (soft, dead soft, etc.)

quicksilver - 10-6-2011 at 10:39

Well for our purposes (as long as the adulterant is not copper) I think that 98% or better is perfectly adequate. The specific grades would be either "Monetary" (which I believe is 99.9%-99.99%) or jewelry quality which may be 98%. Alfa Asar and other chemical firms that sell elements DO have what was commercially know as "Puratonic" 100%?










'








The WiZard is In - 10-6-2011 at 10:54

Quote: Originally posted by dabeak  
You can buy scrap silver and purify it too. A lot of silver used for film (mostly xray film now)


X-ray film? Forsooth, when was the last time you had a X-ray, other then at your dentist?

I remember years back when Paramount (?) pictures moved
out of their W 58 street building in Manhattan - they threw a
dumpster full of 8x10" B&W negatives. I probable could have
bought something really nice if I had salvaged them and taken
them to the recyclers.


djh
----
Speaking of energetic materials —
anyone remember the Cleveland
Clinic X-ray film fire.

Bhaskar - 12-3-2012 at 02:37

Shouldn't This thread be in general chemistry ?

[Edited on 06-10-2011 by Bhaskar]

[Edited on 06-10-2011 by Bhaskar]