Brown substance precipitating gold form AR solution with SMB

[Renaldas]

What happens in this case if not all nitric is eliminated? I tryied to add SMB by drops in HCl-Cl solution, there is no change of a drop of SMB immediatly after it touches the solution. Then I do the same in AR solution, there is brown substance forming, after the drop of SMB touches the solution. This brown substance immediatly dissolves, and after a little time gold began to precipitate. I think, can it be due to some remaining nitric acid?

 

[4metals]

The brown that forms is gold dropping out of the solution. It will redissolve if any free nitric acid is present. This will continue until the nitric is consumed from re-dissolving all of the gold you drop with SMB, then the gold will remain precipitated and settle in the vessel. It is desirable to eliminate the free nitric by either boiling with HCl additions or using urea. Then the gold that drops will not redissolve.

 

[Renaldas]

The brown that forms is gold dropping out of the solution. It will redissolve if any free nitric acid is present. This will continue until the nitric is consumed from re-dissolving all of the gold you drop with SMB, then the gold will remain precipitated and settle in the vessel. It is desirable to eliminate the free nitric by either boiling with HCl additions or using urea. Then the gold that drops will not redissolve.

I'll show you it on video, i think, this is not gold, this is some kind of reaction product between SMB and AR.

 

[Barren Realms 007]

The brown that forms is gold dropping out of the solution. It will redissolve if any free nitric acid is present. This will continue until the nitric is consumed from re-dissolving all of the gold you drop with SMB, then the gold will remain precipitated and settle in the vessel. It is desirable to eliminate the free nitric by either boiling with HCl additions or using urea. Then the gold that drops will not redissolve.

I'll show you it on video, i think, this is not gold, this is some kind of reaction product between SMB and AR.

Where is the video? 8)

 

[samuel-a]

The brown that forms is gold dropping out of the solution. It will redissolve if any free nitric acid is present. This will continue until the nitric is consumed from re-dissolving all of the gold you drop with SMB, then the gold will remain precipitated and settle in the vessel. It is desirable to eliminate the free nitric by either boiling with HCl additions or using urea. Then the gold that drops will not redissolve.

I'll show you it on video, i think, this is not gold, this is some kind of reaction product between SMB and AR.

when copper is also in solution with gold, the addition of SMB will create brown bubbles that will disipate immediately.
this is happning also in a nitric free solution...

 

[Renaldas]

The brown that forms is gold dropping out of the solution. It will redissolve if any free nitric acid is present. This will continue until the nitric is consumed from re-dissolving all of the gold you drop with SMB, then the gold will remain precipitated and settle in the vessel. It is desirable to eliminate the free nitric by either boiling with HCl additions or using urea. Then the gold that drops will not redissolve.

I'll show you it on video, i think, this is not gold, this is some kind of reaction product between SMB and AR.

Where is the video? 8)

I forgot about this
Tomorrow, I swear

 

[Renaldas]

The brown that forms is gold dropping out of the solution. It will redissolve if any free nitric acid is present. This will continue until the nitric is consumed from re-dissolving all of the gold you drop with SMB, then the gold will remain precipitated and settle in the vessel. It is desirable to eliminate the free nitric by either boiling with HCl additions or using urea. Then the gold that drops will not redissolve.

I'll show you it on video, i think, this is not gold, this is some kind of reaction product between SMB and AR.

Where is the video? 8)

I forgot about this
Tomorrow, I swear

Lets watch. This is AR solution, I'm adding SMB, you may see brown substance forming as SMB touches AR solution. After a moment this brown substance dissolves, and gold begin to precipitate. Do you think this may be gold?

http://www.youtube.com/watch?v=aAWmYKwE_OE

 

[Barren Realms 007]

I can barely tell because I had to turn my computer on it's side to watch, but that looks like you still have some nitric in the solution and it is redisolving your gold.

 

[Renaldas]

I can barely tell because I had to turn my computer on it's side to watch, but that looks like you still have some nitric in the solution and it is redisolving your gold.

Sorry for inverted video, my brother turned the camera in wrong direction
Do you think this brown substance is gold?

 

[Barren Realms 007]

I can barely tell because I had to turn my computer on it's side to watch, but that looks like you still have some nitric in the solution and it is redisolving your gold.

Sorry for inverted video, my brother turned the camera in wrong direction
Do you think this brown substance is gold?

I am not sure of that one. Didn't react the way I would think it would.

 

[lazersteve]

The color of the solutoin looks like it may contain iron.

Are you sure you are using sodium meta bisulfite and not sodium meta bisulfate?

The precipitate I see looks red colored, maybe slightly brown, again it's hard to see the precipitate in solution on the video.

Steve

 

[Renaldas]

The color of the solutoin looks like it may contain iron.

Are you sure you are using sodium meta bisulfite and not sodium meta bisulfate?

The precipitate I see looks red colored, maybe slightly brown, again it's hard to see the precipitate in solution on the video.

Steve

Yes, it may easily contain iron. I'm sure I'm using metabisulfite, not bisulfate. Precipitation occurs after a minute, I see a brown powder on a bottom of my glass.

 

[chemist]

If the solution still contained nitric, then we should have seen some red gas (NOxx) being produced as the precipitated gold reacted with the remaining nitric.
Did you see any gas after the camera turned off?

 

[Renaldas]

If the solution still contained nitric, then we should have seen some red gas (NOxx) being produced as the precipitated gold reacted with the remaining nitric.
Did you see any gas after the camera turned off?

No, I see no gas, only strong smell of SO2.