need assistance,i dont understand what is hapening

[ericrm]

ok first this is what i used

home made nitric acid from
dilute sulfuric acid from sulfuric cell (about 1 part 98%h2so4 for 3 part tap water)
nitrate 16-0-0 fertilizer

i was still getting salt in myt nitric acid even after cooling so i chosed to use it anyway...
the acid apeared to be realy week since it was poorly reacting with copper in my first test

so i end up puting my cpu (all ceramic, no gold lid)in my home mad nirtic acid
get it heated for more reaction and... not looking blue as i expected but rather barf green...
i a bit lost i dont have put any chlorine in, no hcl,no clorox,not even salt ,no cross contamination...it cannot a made aqua regia but still watch the picture(sncl test) i have disolved gold.... what do you think happen?

i have smell it ,thinking that might be a false opistive but it doesnt stink...

 

[Geo]

could be silver.

 

[butcher]

I believe you dissolved gold, your stannous chloride looks positive to me, I would say your nitrate salts (fertilizer or whatever) had chlorides in them, this is not surprising to me, as many of these nitrates are mined, their use for fertilizers and stump removers, do not requiring purification of all of the chlorides they may contain naturally.

Here is a test and a way to remove chlorides from your nitric acid, first I will give some statements.

Silver forms insoluble chlorides, this can look like milky substance in solution, or can precipitate as white solids.
If we have a nitric acid solution it will dissolve silver.
If we have silver it will form a passivation layer in HCL and not dissolve much at all forming this protective white crust.
to form aqua regia we can have different amouts of nitric and HCL, any chloride (salt)(CL-), in nitric acid HNO3, would join with the acidic hydrogen (H+) and form:
(H+) + (Cl-) --> HCL
now we have a little HCl in a lot of HNO3, so we will dissolve as much gold as the HCl in our nitric acid can take into solution at that temperature.

Now or test nitric acid with some dissolved chloride in solution,
If I add silver nitrate (dissolved silver), the silver will form silver chloride and show up as a white milky insoluble and precipitate out as white powder, if we decant our nitric from this we have removed the chloride from solution with the silver.

 

[Dr. Poe]

ok first this is what i used

home made nitric acid from
dilute sulfuric acid from sulfuric cell (about 1 part 98%h2so4 for 3 part tap water)
nitrate 16-0-0 fertilizer

i was still getting salt in myt nitric acid even after cooling so i chosed to use it anyway...
the acid apeared to be realy week since it was poorly reacting with copper in my first test

so i end up puting my cpu (all ceramic, no gold lid)in my home mad nirtic acid
get it heated for more reaction and... not looking blue as i expected but rather barf green...
i a bit lost i dont have put any chlorine in, no hcl,no clorox,not even salt ,no cross contamination...it cannot a made aqua regia but still watch the picture(sncl test) i have disolved gold.... what do you think happen?

i have smell it ,thinking that might be a false opistive but it doesnt stink...

Nitrosulfuric acid is known to slowly dissolve gold, especially when hot. Dr. Poe

 

[butcher]

Thanks Doc,

Here some discussion:
http://www.sciencemadness.org/talk/viewthread.php?tid=17164

Fleaker on that forum is one of the chemist here on our forum.

 

[goldsilverpro]

Thanks Doc,

Here some discussion:
http://www.sciencemadness.org/talk/viewthread.php?tid=17164

Fleaker on that forum is one of the chemist here on our forum.

Fleaker is Lou.

Anders Hoveland was a member here for a few days. If I remember right, he was banned.

Technically, the last person on the planet I would disagree with is Lou. However, I also have done a lot of wet ashing of filter papers and cyanide gold solution samples, on a very small scale, using hot conc. H2SO4 with small occasional additions (dropwise) of nitric acid. After the black carbon is gone, the solution is usually water-clear, so you can easily see what is happening. The gold precipitates as a powder or sponge. On quite a few occasions, immediately after adding a few drops of nitric, the gold powder would disappear (dissolve). After the nitric was dispelled (I assume), the gold powder would re-precipitate.

Chemically, I have no idea of why this happened.

 

[butcher]

I read that as, Fleaker saying (it was not a practical way to dissolve gold), (not that gold might not go into solution at some degree).

Also it speaks of one our forum and a member saying that some gold would go into solution, but was not practical to use, to dissolve gold, I thought they may have read one of GSP’s posts.

 

[ericrm]

finaly
i realy think that my solution was full of metalic silver,it have taken 3 day to settle but i have a think gray precipitate on the bottom and the solution is dirty green ,realy like when you have to much copper in hcl cl...
i have filtrate end put copper in to cement everything out,it is working well.
when i will know more i will post again

 

[Geo]

umm, very quietly i said "could be silver" . :lol:

actually, Harold set me straight with the effect. silver in solution will cause a purple stain with stannous (sometimes).

 

[freechemist]

Cited from Geo:"actually, Harold set me straight with the effect. silver in solution will cause a purple stain with stannous (sometimes)".

For testing a solution of SnCl2 in aqueous HCl is used. If the solution to be tested contains silver, on addition of SnCl2-solution, silver chloride is precipitated. AgCl is fotosensitive and rapidly darkens on exposure to light, hence the dark stains on the paper shown by ericmr's picture.

freechemist