I as well lurked for several weeks before posting. You lurk by using google. I kept doing searches on how to refine stuff, make nitric, where to buy chemicals, etc. this forum kept popping up so I thought I'd stick around. I had everything planned out and ready to go before even posting. I believe my first post was something along the same lines and process as corvette, but I think my question was more "my homemade nitric doesn't dissolve silver"
That sounds pretty nearly the procedure I did. Little different numbers, but close. sulfuric should be added very slowly, and keep track of the temperature - stop adding sulfuric if it gets close to boiling, and stir constantly.
As the solution is cooled, sodium sulfate will precipitate out of solution (eventually bring it all the way to -20ºC, which is a typical freezer's temperature). After that happens, that's when you decant the liquid through a filter
yellow liquid sounds promising (yellow tint comes from NOx gasses dissolved in it)
a couple ways I know of to distinguish nitric from sulfuric acid:
- see what it dissolves. does it dissolve silver? copper? iron?
- put a small amount (less than a ml) in a small beaker (I have this adorable 10 ml borosilicate beaker that would be perfect for this). with proper safety precautions (acid fumes are VERY toxic), apply heat so it evaporates the liquid without boiling, keep it under 100ºC. When it stops evaporating, observe it. I would expect some crystals (sodium sulfate has low solubility, but not 0, also maybe some sodium nitrate left). If there is still liquid, that liquid is sulfuric acid (sulfuric does not vaporize near water's boiling point). If no liquid, the nitric evaporated.
Also, you should know that the nitric you make is not very suitable for dissolving silver. there will be sodium sulfate left in there, which will react with silver nitrate to form solid silver sulfate
