Stannous / Ammonia Test Color List - Chat GPT - Request Assistance

[fredtest]

I've been looking for a master list of test colors. I figured I'd try out Chat GPT and below is what it coughed out after some back and forth dialog. (I'm just learning hobby chemistry so please be gentle.)

Initially the results look correct but I was hoping to have more eyes look over the results. I've learned Chat GPT results are often incorrect.

My entry text:
"Generate a list for the following metals: iron, cadmium, cobalt, nickel, tin, lead, antimony, bismuth, copper mercury, silver, gold, platinum, palladium. Add the stannous test colors and ammonia test colors to this list for each metal."


ChatGPT
Certainly! Here's a comprehensive list for the metals you mentioned, including the Stannous test colors and ammonia test colors:

1. Iron (Fe):
   • Stannous test color: Brown
   • Ammonia test color: Green precipitate ([Fe(H2O)6]²⁺ complex ion, then turns green with excess ammonia)
2. Cadmium (Cd):
   • Stannous test color: White
   • Ammonia test color: White precipitate (forms Cd(NH₃)₄²⁺ complex)
3. Cobalt (Co):
   • Stannous test color: Pink
   • Ammonia test color: Blue (forms Co(NH₃)₆²⁺ complex)
4. Nickel (Ni):
   • Stannous test color: Green
   • Ammonia test color: Green precipitate ([Ni(H2O)6]²⁺ complex ion, then turns green with excess ammonia)
5. Tin (Sn):
   • Stannous test color: Yellow
   • Ammonia test color: White precipitate (forms Sn(NH₃)₆²⁺ complex)
6. Lead (Pb):
   • Stannous test color: Yellow
   • Ammonia test color: White precipitate (forms Pb(NH₃)₄²⁺ complex)
7. Antimony (Sb):
   • Stannous test color: Not well-defined, can vary
   • Ammonia test color: White precipitate (forms Sb(NH₃)₆³⁻ complex)
8. Bismuth (Bi):
   • Stannous test color: Not well-defined, can vary
   • Ammonia test color: White precipitate (forms Bi(NH₃)₅³⁻ complex)
9. Copper (Cu):
   • Stannous test color: Reddish-brown
   • Ammonia test color: Blue (forms [Cu(NH₃)₄]²⁺ complex)
10. Mercury (Hg):
    • Stannous test color: White
    • Ammonia test color: White precipitate (forms Hg(NH₃)₂ complex)
11. Silver (Ag):
    • Stannous test color: Not applicable
    • Ammonia test color: White precipitate (forms Ag(NH₃)₂⁺ complex)
12. Gold (Au):
    • Stannous test color: Purple
    • Ammonia test color: Purple-black (forms Au(NH₃)₄⁺ complex)
13. Platinum (Pt):
    • Stannous test color: Yellow or brown
    • Ammonia test color: Yellow precipitate (forms Pt(NH₃)₄²⁺ complex)
14. Palladium (Pd):
    • Stannous test color: Dark brown or black
    • Ammonia test color: Dark brown precipitate (forms Pd(NH₃)₄²⁺ complex)

These colors represent typical reactions of the metal ions with stannous chloride and ammonia, providing qualitative information about the identity of the metal ions.

My entry text: Are these colors for nitrate salts or chloride complexes?

ChatGPT
The colors provided in the lists are generally associated with reactions involving metal ions, whether they are from nitrate salts or chloride complexes. The colors are often observed during reactions with specific reagents, such as stannous chloride or ammonia, and the specific anion (nitrate or chloride) may not always be explicitly mentioned.
In many cases, the specific anion accompanying the metal ion can influence the behavior of the metal ion in solution, but certain tests may focus on the metal cation's characteristics rather than the accompanying anion.
For example, the Stannous test is a qualitative test that can be used to identify certain metal ions, and it involves the reaction of stannous chloride with metal ions in solution. The resulting colors are indicative of the presence of specific metal ions, and the test is not specific to a particular anion like nitrate or chloride.
Similarly, the ammonia test involves the reaction of metal ions with ammonia, forming various metal-ammonia complexes. Again, the specific anion (nitrate or chloride) is not always crucial in these qualitative tests.
In laboratory settings, the choice of reagents and the conditions of the reaction may be adjusted depending on the specific goals of the analysis.

 

[Martijn]

Very interesting list, but i would not rely on it too much.
Stannous e.g. is made from Tin, and i think it stay's colorless in stead of yellow. I could be wrong.
With silver, you are adding a form of chloride to it (SnCl) with free HCl, so stannous should give AgCl in stead of nothing.
there are surely other exceptions in this list.

 

[fredtest]

Hello Martijn.
I agree, Thank you for the reply.

 

[Ultrax]

Very interesting list, but i would not rely on it too much.

I totally agree. Using ChatGPT to obtain reliable scientific information is the same as hiring a yellow tabloid journalist as a corporate lawyer.

 

[kurtak]

ChatGPT
Certainly! Here's a comprehensive list for the metals you mentioned, including the Stannous test colors and ammonia test colors:

This list is in no way "comprehensive" & in fact provides some false information

Tin (Sn):

• Stannous test color: Yellow

This is not true - stannous chloride "in the first place" is made by dissolving tin with HCl - the result of that is a "perfectly" (water) clear solution --- so if you test stannous chloride with stannous chloride you will get "absolutely" NO result --- in other words adding a drop of clear stannous chloride to a clear solution of stannous chloride is not going to give a yellow result - because both solutions are the same thing --- you can't test stannous chloride with stannous chloride --- tin does not dissolve in nitric - it turns the tin to a white paste known as stannic acid

Lead (Pb):

• Stannous test color: Yellow

This will result in a white precipitate (not yellow) of lead chloride - very much like silver chloride

Silver (Ag):

• Stannous test color: Not applicable

Not true - adding stannous chloride to a silver solution will result in precipitating "white" silver chloride (like lead chloride) the difference being that lead chloride does not photo grey when exposed to light whereas silver chloride does --- in other words lead chloride when exposed to light remains white & on the other hand the white silver chloride when exposed to light will turn a purple/grey color & even go black if exposed long enough to the light

Platinum (Pt):

• Stannous test color: Yellow or brown

Not true - stannous test for Pt should be orange - a "bright" orange & if Pt concentration is high enough lean to deep (& bright) red/orange

Palladium (Pd):

• Stannous test color: Dark brown or black

Not true - a stannous test for Pd should be a deep forest green (not a light lime green) --- that said - when you first add stannous to a Pd solution it can sometime first show up as an orange/red color (much like Pt) but should then shift to the forest green that indicates Pd

See the colors for Pt & Pd as posted in the picture provide by Yaggdasil in this thread -------

https://goldrefiningforum.com/threads/sodium-chlorate-palladium-process.29659/
One more note to make here --- if you have Mo (molybdenum) in solution it (stannous) can give a "false positive" that looks very much like Pt orange --- you can test to make sure it is Pt & not Mo by dipping a piece of copper wire in the solution - if it is Pt the Pt will plate to the copper - if it is Mo it won't plate to the copper

Kurt

 

[Lou]

Yep, it’s more wrong than right!

 

[4metals]

I cannot count how many images we've seen here asking to interpret the results of a stannous test. In a solution with many other metals dissolved it can get very difficult to rely solely on stannous chloride for anything other than gold. And for dilute gold with a ton of other unspecified crap it is even more difficult. I think Fredtest is overthinking the use of stannous. If you need to know all of the metals listed choose another method. Keep in mind one thing, one very simple thing. Stannous chloride is your eyes for a quick test to determine if gold is present in an acid solution. It's purple to black instantaneous result is unmistakable and the dark result blots out all other indications visible when gold is not present.

So keep it simple, when testing if gold is in solution a quick very dark purple to black result tells you you have gold. When precipitating Gold the lack of the quick dark result tells you you have dropped all of the gold. When all of the gold is dropped the stannous can tell you if there is Platinum or Palladium in solution because those colors, which often develop slower, are masked by the strong indication given by a positive gold test.

A quick drop test such as stannous is not meant to be the ultimate indicator. Makeup clean solutions of Gold,Platinum,Palladium and even Rhodium and test them with a stannous solutions. Learn the eyes on results. All the chat in the world will never replace the hands on experience you get from doing it yourself.

If you need to test all of the other metals Chat tells you stannous will indicate, ask chat if they have an Atomic Absorption for sale cheap.

edited to add paragraph about hands on testing.

 

[Yggdrasil]

This list is in no way "comprehensive" & in fact provides some false information


This is not true - stannous chloride "in the first place" is made by dissolving tin with HCl - the result of that is a "perfectly" (water) clear solution --- so if you test stannous chloride with stannous chloride you will get "absolutely" NO result --- in other words adding a drop of clear stannous chloride to a clear solution of stannous chloride is not going to give a yellow result - because both solutions are the same thing --- you can't test stannous chloride with stannous chloride --- tin does not dissolve in nitric - it turns the tin to a white paste known as stannic acid

This will result in a white precipitate (not yellow) of lead chloride - very much like silver chloride

Not true - adding stannous chloride to a silver solution will result in precipitating "white" silver chloride (like lead chloride) the difference being that lead chloride does not photo grey when exposed to light whereas silver chloride does --- in other words lead chloride when exposed to light remains white & on the other hand the white silver chloride when exposed to light will turn a purple/grey color & even go black if exposed long enough to the light


Not true - stannous test for Pt should be orange - a "bright" orange & if Pt concentration is high enough lean to deep (& bright) red/orange

Not true - a stannous test for Pd should be a deep forest green (not a light lime green) --- that said - when you first add stannous to a Pd solution it can sometime first show up as an orange/red color (much like Pt) but should then shift to the forest green that indicates Pd

See the colors for Pt & Pd as posted in the picture provide by Yaggdasil in this thread -------

https://goldrefiningforum.com/threads/sodium-chlorate-palladium-process.29659/
One more note to make here --- if you have Mo (molybdenum) in solution it (stannous) can give a "false positive" that looks very much like Pt orange --- you can test to make sure it is Pt & not Mo by dipping a piece of copper wire in the solution - if it is Pt the Pt will plate to the copper - if it is Mo it won't plate to the copper

Kurt

Important note. The picture comes from Lazersteve not me.
I just use it for educational purposes and forgets to give proper credit from time to time.

 

[fredtest]

Thanks for all the wonderful reply's.

4metals - The stannous test changing color with time was really confusing for me. I would do a test write down the color, come back to the same tube now a different color and think what is going wrong. Your reply is a huge help.

Luckily a buddy of mine mentioned numbering all vessels and taking notes to the contents/processes. That has been a huge help for me. Before I was going from memory and with 15 concoctions going I was getting lost.

kurtak - Thanks for mentioning the ChatGPT errors.

As for ChatGPT, Recently I've used it to create roughed out Python code which took around 6 to 10 iterations to get working for simple gui with serial communications, real time plotting and storage of data to a file. It's best to start with a simple function and then build on that. Often times ChatGPT gets horribly lost with revisions. When ChatGPT would fail to generate a working version I tell it to add this function and paste in a previous working version.
It is definitely a useful tool to create approximate code. LOL If you want working code, human intervention is still needed. I do find it satisfying to see a huge listing pop out in so short of time. I feel like a boss with a very fast worker. Unfortunately the worker is not so talented but it is apologetic. Me: The code fails to reply data. ChatGPT: I'm Sorry... Here's the working version.
Next time I'll tell ChatGPT to call me "Master" for fun. ChatGPT: I'm Sorry Master ... Here's the working version.

Cheers Fellows,
Kevin Hawes

 

[kurtak]

So keep it simple, when testing if gold is in solution a quick very dark purple to black result tells you you have gold. When precipitating Gold the lack of the quick dark result tells you you have dropped all of the gold. When all of the gold is dropped the stannous can tell you if there is Platinum or Palladium in solution because those colors, which often develop slower, are masked by the strong indication given by a positive gold test.

Yes - if you have Pd &/or Pt in solution along with gold the gold can/will have a tendency to "mask" the Pd &/or Pt in the stannous test - this is especially true if you do the test in a spot plate (instead of on a Q-tip or on paper)

That is because in a spot plate test the metals are very homogeneous in the solution so the deeper/darker purple/black of the gold will "mask" the Pd/Pt that are also in solution

In fact (at least in my experience) if Pd & gold are in solution the test result can/will be VERY black instead of a purple/black (black with a purple hue) & that is due to green/black (black with a green hue) normally seen with just Pd mixing with the gold purple/black - in other words purple/black plus green/black = VERY black

That is in a spot plate test (at least in my experience)

However (also in my experience) if you suspect Pt &/or Pd in solution with your gold & you do your stannous test with a Q-tip &/or on paper the Pt &/or Pd can/will also show up in the test

Examples ----------

1) Q-tip - dip Q-tip in solution - add drop of stannous to the very tip of the cotton swab & it will go jet black (very black) however - at the other end (where the cotton meets the stick the swab is attached to) is where the Pt &/or Pd colors will show up - so green - or - orange can/will show up at the stick end of the swab --- this is best done with a Q-tip on a paper stick (rather then plastic stick) as the Pt &/or Pd colors will creep a bit up the paper stick

2) on paper (paper towel or filter paper) put drop of solution on paper - add drop of stannous to one edge of solution drop - where stannous first hits the solution drop it will go jet black - but then as the test result "fans out" from first contact point (in other words outer edges of test) the Pt &/or Pd colors should show up

Personally I prefer the Q-tip

Side note; - I believe it was Lazersteve that taught me this "many" years ago

This is not an absolute as the gold can/may completely mask the Pt/Pd - but it is something you should watch for because if the stannous test shows an "indication" (as described above) of PGMs in the solution (with gold) it can make a difference in how you go about dropping the gold from the solution

Examples -----------

1) you certainly would not want to cement with copper (to "recover" gold from a VERY dirty solution) - as that will also drag down all the PGMs

2) dropping the gold with SMB is NOT your best choice of precipitant as SMB has a tendency to drag "some" of the PGMs along with the gold drop

3) so FeSo4 (copperas) for dropping the gold is a better choice of precipitant as FeSo4 has "less" tendency to drag the PGMs down with the gold drop

One more side note; - if you have all tree (Au/Pt/Pd) in solution & IF the Pd green shows up in the stannous test (as describe above) it is likely to mask the Pt orange (though I have had test results where all three show up)

For what it is worth

Kurt

 

[kurtak]

Important note. The picture comes from Lazersteve not me.
I just use it for educational purposes and forgets to give proper credit from time to time.

Yes - you are absolutely right in pointing out that it was Lazersteve that provided that stannous test results pic many years ago & thank you for pointing that out as that pic posted by Steve so many years ago now has been an important tool in helping members know the true stannous test results we look for in the metals we target

THANK YOU STEVE !!!!

Kurt

 

[4metals]

Details, details, details. Everything Kurt says is absolutely true, sometimes. And everything I said is absolutely true, sometimes. And it all depends on what you are refining and the concentrations of the different PM's in solution.

Let me explain. The vast majority of the refiners I deal with primarily refine jewelry. That means the majority of the values in solution is from the gold. But often there are a few findings that are Platinum with a little Palladium in the alloy. The PM's in this case are in very low concentrations compared to the Gold. In this case the Gold stain is predominant and the low concentrations of Platinum and Palladium rarely show up in the stain until the Gold has been dropped. After the gold has dropped the Platinum stain shows up, often very faint, and that tells me the waste liquor goes in the PGM recovery waste bucket. This is true for most all karat jewelry refining.

But these same refiners also process some dental scrap. Now the Gold and Palladium content can be equal in solution. In this case the wicking action that separates the Gold stain from the PGM stain that Kurt mentioned can be seen. I should say here that I am spoiled, because in this case I would simply slap in a Platinum lamp on the Atomic Absorption and quantify the Platinum or Palladium as the case may be. I use the stannous as a quick indicator to tell me when the drop of the Gold is complete. (and yes ferrous sulfate is better if PGM's are high). Then I cement the PM's on copper dust and end up with cleaner PM's to re-digest and process separately.

A third case can be made for slimes from electrolytic e-scrap refining, the PGM's are higher than in typical karat scrap but not as high as in dental. Again I (spoiled as I am with a decent lab) use the stannous to tell me when the gold is down and process the balance of the PM's accordingly.

I guess the moral of the story is any of this stuff is dependant on what type of scrap you started with and your methods. Which is why all of the mods and members with refining experience always ask for specific details..... because it matters!

I should mention that stannous chloride is also quite valuable for a quick determination of whether or not your waste solutions contain any residual PM's. This is always indicated by a weak slow to develop stain but it is something you will learn to recognize. I always separate my wastes by a stannous determination of PM's or not. All of my waste is cemented on copper but the wastes which had an indication of PM's via stannous will have a more PM rich sediment layer than the wastes without the positive stannous test. The waste treatment process is identical for both, but the tanks which exhibited a positive PM stain before processing have a happier sludge layer on the bottom!