salter Posted March 31, 2009 Share Posted March 31, 2009 So i decided to grow some silver crystals. The conventional way is dissolve [ce]AgNO3[/ce] in water and put in copper, then the copper dissolves to make copper nitrate and the silver precipitates out. I figured that i would just dissolve silver in nitric acid myself... So my question is this: do I need to separate the [ce]AgNO3[/ce] from the nitric acid or could i saturate the acid with silver then just put in the copper? Link to comment Share on other sites More sharing options...
UC Posted March 31, 2009 Share Posted March 31, 2009 So i decided to grow some silver crystals.The conventional way is dissolve [ce]AgNO3[/ce] in water and put in copper, then the copper dissolves to make copper nitrate and the silver precipitates out. I figured that i would just dissolve silver in nitric acid myself... So my question is this: do I need to separate the [ce]AgNO3[/ce] from the nitric acid or could i saturate the acid with silver then just put in the copper? Well, depends how much nitric acid is left. If you aren't dissolving any more silver with hot acid, I think it would be fine to just cool, pour off the liquid and use it directly. Otherwise the copper and very fine silver crystals will dissolve. Link to comment Share on other sites More sharing options...
coke Posted March 31, 2009 Share Posted March 31, 2009 It probably wouldn't make much of a difference, it would be a bit better if you seperate the crystals first if either you don't want to produce NO2 in the second reaction, or you don't have excess copper...but NO2 will be produced in the first reaction anyways... [ce]Ag + 2HNO3 -> H2O + AgNO3 + NO2[/ce] [ce]2AgNO3 + Cu -> Cu(NO3)2 + 2Ag[/ce] I would think you are trying to dissolve a piece of jewelry or something into scrap silver? Copper nitrate is very pretty by the way. Link to comment Share on other sites More sharing options...
salter Posted April 1, 2009 Author Share Posted April 1, 2009 rewording what i was asking at the beginning... So do I need to use up all of the nitric acid before adding the copper? If both silver nitrate and nitric acid are left, wouldn't the copper rather react with the nitric acid than the silver nitrate? Link to comment Share on other sites More sharing options...
Mr Skeptic Posted April 1, 2009 Share Posted April 1, 2009 rewording what i was asking at the beginning... So do I need to use up all of the nitric acid before adding the copper? If both silver nitrate and nitric acid are left, wouldn't the copper rather react with the nitric acid than the silver nitrate? But if you put excess copper in, would that still matter? Wouldn't it just mean that you use more copper and more acid than you would have otherwise? Link to comment Share on other sites More sharing options...
salter Posted April 1, 2009 Author Share Posted April 1, 2009 Well I'm going to be using different shapes of copper to try to encourage different growth and if the copper reacts with the acid and changes form before the silver starts to precipitate out then it could mess up the shape and growth of the crystal. So then the one last thing I need is a confirmation that the copper would rather react with the nitric acid than with the silver nitrate. Or you could say the opposite was true and that would make me much happier. Link to comment Share on other sites More sharing options...
coke Posted April 1, 2009 Share Posted April 1, 2009 in the case you are trying to grow crystals... (i thought you were just trying to precipitate silver)... it's very hard to say... but if only reacting with silver nitrate will give you crystals, you might as well just put the AgNO3 and nitric acid out in the sun for a couple days, let the acid evaporate... (although i'm not sure AgNO3 may decompose in light) Link to comment Share on other sites More sharing options...
YT2095 Posted April 1, 2009 Share Posted April 1, 2009 I do this rxn on a regular basis (as a photographer), you`ll probably find that your scrap silver, unless bought as a Pure Element will contain traces of copper alloyed in it anyway, I`v found it`s best to use a weak soln of nitric 10-15% and have the silver in excess, but you Can dissolve all of it if you want to. the soln Will go a blue color due to the copper nitrate. the "problem" comes if the acid way in excess and the soln goes too blue, and you can`t see the silver crystals form, they Will form eventually, but you`ll not be able to see them clearly and that`s a shame. also, be prepared to see little more than a gray spongey mass as your silver product! but if your soln isn`t too stong and you leave it undisturbed for a while, you will see it occasionally catch the sunlight and gets little sparkles, it`s even better under a microscope. personally, I extract all my silver this way 1`st, give it a Good wash in deionised water (Chlorine in tap water makes the washing cloudy), and then redissolve it in nitric again to leave a clear silver nitrate soln. Link to comment Share on other sites More sharing options...
hermanntrude Posted April 1, 2009 Share Posted April 1, 2009 I did the simpler version this week. Took some silver nitrate and dumped in a copper coin. Very quickly the coin was covered in beautiful crystals of silver. Of course as soon as you rinse the coin the crystals fall off, but there's a good coating of silver on the coin. Makes it look like a nickel instead of a penny... i'll be rich soon! Link to comment Share on other sites More sharing options...
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