Which element can combine with hydrochloric acid and cause discoloration with stannous chloride ?! I work on minerals. I have encountered this on several occasions. Color change is like changing the color of palladium. I know that palladium oxide can be dissolved with hydrochloric acid. I even used DMG and made sure it was not a palladium discoloration. The color of the solution is also green. Can anyone guide me on what element I am facing?
hydrochloric acid and stannous chloride
- Thread starter yasin1987
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Geo
Well-known member
Palladium will dissolve in concentrated hydrochloric acid while cool and dilute hydrochloric acid when hot. Most precious metals will dissolve in just hydrochloric acid while it is hot and the metal is finely divided powder. Can you post pictures of the solution and the stannous chloride test?
Geo said:
The stones are finely ground. I have done some tests for rhodium and so on. Its pictures:
I think the gray matter is mercury.
1 ml Solution
2 ml Distilled water
1 ml stannous chloride
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The above composition after heat for rhodium test...
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Another test
Soluble paint
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1.5 ml Solution
4 ml Distilled water
A few drops of stannous chloride
And a few hours later ...
Geo
Well-known member
It looks like a positive for PGM's. Palladium will be red/yellow or even blue/green when you first add the stannous chloride and then gradually turn to a deeper green over the course of some minutes time. Rhodium will start red/orange and stay the same color over time. Platinum will give a similar result.
Thank you very much for your time.Geo said:
I'm sure this is not a color change for gold. I also tested with cyanide (Page 91 CM Hokes book). An experiment in which 1 ppm and above can be easily detected.
I do not have enough experience changing the color of Iridium, Rhodium, Ruthenium, Osmium and I do not know their color change.
I'm not sure about the quality of my existing DMG.
I tested with ammonium chloride and found no change.
I'm really confused.
Lino1406 said:
Thank you for your answer. That is, what elements other than PGM and gold can change color with stannous chloride?
I have found many elements in this sample that I send you a part of:
Ag : 15.5 ppm
Al : >2%
As : >100 ppm
Ba : 306 ppm
Be : <1 ppm
Ca : 4863 ppm
Cd : 3.4 ppm
Ce : 32 ppm
Co : 85 ppm
Cr : 21 ppm
Cu : >2%
Fe : >2%
K : >2%
La : 24 ppm
Li : 10 ppm
Mg : 3828 ppm
Mn : 2636 ppm
Mo : 234.5 ppm
Na : 3064 ppm
Ni : 44 ppm
P : 1074 ppm
Pb : 1033 ppm
S : 5926 ppm
Sb : 76.4 ppm
Sc : 7.5 ppm
Sr : 67 ppm
Th : <5 ppm
Ti : 1614 ppm
U : <5 ppm
V : 82 ppm
Y : 30 ppm
Yb : 2.3 ppm
Zn : 491 ppm
Zr : 7 ppm
Lino1406 said:
Elements with empty d shell positions have colored chlorides. PM's - additionally - end stannous chloride reaction as black sponge (gold - brown)
I did not understand the exact meaning. Can you explain more? My English is not that good
:?Sorry this is chemistry, not English. Transition metals, including PM's have that property - empty d positions, hence colored compounds. In short - electrons passing between d and s positions need energies in the visible spectrum range.
Lino1406 said:
Thank you for your excellent explanation. Atomic orbital and spd. I remembered and had to study again.
But among the transition metals, I have done many tests.
Usually, when we work with AR and when we have not eliminated its nitrate, stannous chloride causes discoloration for copper, iron, etc.
But after removing nitrate, stannous chloride does not change color with iron, copper, zinc, nickel, cadmium, silver, etc.
I'm really confused.
Find Transition metals and test individual elements. That is, no one has tested this before?
Lino1406 said:
I do not know where I read before, (perhaps Hoke's book) that a cotton pad is not suitable for tin chloride testing. But again with the available elements I can do the experiment with a cotton pad.
I do all my tests on Spot plate Or a plastic spoon.
This is an example of a mineral. Green Veins can usually be found within a radius of 500 km. They all have the same properties.
After dissolution with hydrochloric acid and stannous chloride test, they turn black.
Usually the blue color in these minerals can be considered as gold.
Lino1406 said:
I am from Turkey. I did the steps again. And only hydrochloric acid with a little heat.
2.5 ml Solution
1 ml Distilled water
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A few drops of stannous chloride
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I added a little water to it and a few drops of stannous chloride
What could this be?
