Hello guys,
Please help me identify the metal I received (!).
I dug out a small piece of unusual coal shale (about 100 g), the oxides of which seemed strange to me under a microscope, and I decided to test it for the presence of platinum metals.
I crushed the shale into dust with a mill and filled everything with fairly strong nitric acid 30%.
Hydrogen sulfide immediately went out, it smelled terribly of rotten eggs, but after a few minutes, the reaction stopped, and the solution turned slightly greenish-brown but remained transparent.
I set the solution aside and poured the viscous sediment with aqua regia.
After the aqua regia was evaporated and the sediment melted, it turned out that there was 0.1 g of gold in a piece of coal shale.
I also decided to check the same nitric acid solution, which I first set aside.
I put a piece of polished copper in it and left it for a day.
A day later, the solution darkened and turned brown, and at the bottom, there was a yellowish precipitate similar in color to iron hydroxides (which, in theory, could not be, copper, should not precipitate iron in acidic solutions).
Anyway, I added 100 ml of ordinary acetic acid 10% to this solution to remove, as it seemed to me, iron hydroxides. But nothing happened, the precipitate did NOT dissolve, it became denser and acquired an orange tone.
I drained the solution, and separated the precipitate after drying (2 g) - it became a beautiful, very bright yellow-orange color.
Tell me, what could it be? Could it be palladium acetate? But my nitric acid solution was not originally red?
What else could be precipitated by copper from my solution of nitric acid, except for platinum metals?
Thanks for any help!
Please help me identify the metal I received (!).
I dug out a small piece of unusual coal shale (about 100 g), the oxides of which seemed strange to me under a microscope, and I decided to test it for the presence of platinum metals.
I crushed the shale into dust with a mill and filled everything with fairly strong nitric acid 30%.
Hydrogen sulfide immediately went out, it smelled terribly of rotten eggs, but after a few minutes, the reaction stopped, and the solution turned slightly greenish-brown but remained transparent.
I set the solution aside and poured the viscous sediment with aqua regia.
After the aqua regia was evaporated and the sediment melted, it turned out that there was 0.1 g of gold in a piece of coal shale.
I also decided to check the same nitric acid solution, which I first set aside.
I put a piece of polished copper in it and left it for a day.
A day later, the solution darkened and turned brown, and at the bottom, there was a yellowish precipitate similar in color to iron hydroxides (which, in theory, could not be, copper, should not precipitate iron in acidic solutions).
Anyway, I added 100 ml of ordinary acetic acid 10% to this solution to remove, as it seemed to me, iron hydroxides. But nothing happened, the precipitate did NOT dissolve, it became denser and acquired an orange tone.
I drained the solution, and separated the precipitate after drying (2 g) - it became a beautiful, very bright yellow-orange color.
Tell me, what could it be? Could it be palladium acetate? But my nitric acid solution was not originally red?
What else could be precipitated by copper from my solution of nitric acid, except for platinum metals?
Thanks for any help!
