Silver Nitrate briefly exposed by accident to light is ruined?

rafaelmotta

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An unauthorized person was messing arround with the college Silver Nitrate, and had opened it for kind of half a minute (until I see it) . The chemical is ruined out or I can try to work with it? It was about 100 grams of silver nitrate.
 

Barry S

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Silver nitrate needs to react with organic compounds or halide salts in order to become light-sensitive. You can open it in the light without any problems.
 

Gerald C Koch

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Silver nitrate is not particularly sensitive to light. It would take a very long exposure to cause a visual change in the crystals. Still it should be in a brown glass bottle and kept in a dark location such as a cabinet.
 

David A. Goldfarb

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Albumen and salt printers even expose silver nitrate solution to the sun to clear it between uses before using it to sensitize salted paper.
 

NedL

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And actually I'd be interested to hear more about how people "sun" their silver nitrate. I know you set a clear bottle of AgNO3 solution in the sun, and then filter it, and the idea is that somehow the sunlight forces the silver nitrate to bind to impurities.... but how about all the details like how long, how often, how to filter, and so on????
 

David A. Goldfarb

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Mark Osterman has mentioned it on facebook. I asked him once, and he said that they sun the silver nitrate in a big glass jar in the summers, but use kaolin when there isn't enough sun. I've used kaolin, but haven't tried sunning yet.

I don't think the process is that mysterious. One does it when gunk appears to be in the solution, and it should probably stay out until it looks clear. With kaolin, I decant and let it settle and decant again, repeating about three times, and then filter through filter paper like a coffee filter, and I don't see why that shouldn't work with sunning as well.
 

NedL

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So when you are done, you have removed the kaolin? Interesting. My impression from Alan Greene's book is that he leaves the kaolin in the bottle with the silver nitrate solution... occasionally shaking it up and then letting it settle well before decanting through a filter for use. I need to do one of these things soon, my calotype sensitizing solution is starting to look, well, cloudy with tiny black specks in it... so far I have only filtered it and that has worked, but it's not a long term answer.

Thanks!
 

cliveh

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In crystal form it has little sensitivity.
 
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David A. Goldfarb

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I filter the kaolin from the solution to put it into a clean bottle, but I leave the kaolin in a bottle that I use for filtering (a large vodka bottle that has a convenient shape for decanting) and then pour it back into that bottle when it's time to filter again.
 
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