Sciencemadness Discussion Board

Cu(NO3)2 + Sn = ?

Romix - 9-10-2025 at 08:32

CuNO3 + Sn = Stannic acid and no visible displacement, nitrate was lightly acidic.



[Edited on 9-10-2025 by Romix]

chempyre235 - 9-10-2025 at 10:36

Did you get any fumes? Any precipitate? Color shift?

Romix - 9-10-2025 at 10:39

Quote: Originally posted by chempyre235  
Did you get any fumes? Any precipitate? Color shift?
No fumes, precipitate white jelly Stannic acid, blue solution before and after addition of Sn.
DSC00099.JPG.2a955dd456bbf3d35ae045b8eb751db7.jpg - 128kB

[Edited on 9-10-2025 by Romix]

DraconicAcid - 9-10-2025 at 10:57

Odd. Surely you mean Cu(NO3)2, btw.

How long did you leave it?

Romix - 9-10-2025 at 11:06

Quote: Originally posted by DraconicAcid  
Odd. Surely you mean Cu(NO3)2, btw.

How long did you leave it?

Yes, sorry, wrong valency, precipitate formed almost immediately.

bnull - 9-10-2025 at 11:14

The nitrate, was it bought or you made it?

DraconicAcid - 9-10-2025 at 11:15

The stannic hydroxide ppt is going to be voluminous. Leaving it sitting for a while, and you'll probably start to see copper metal forming.

Romix - 9-10-2025 at 11:18

Quote: Originally posted by bnull  
The nitrate, was it bought or you made it?

I made it.

Romix - 9-10-2025 at 11:19

Quote: Originally posted by DraconicAcid  
The stannic hydroxide ppt is going to be voluminous. Leaving it sitting for a while, and you'll probably start to see copper metal forming.

Was there for couple of days, with out any visible displacement.
Maybe not enough Sn and solution too acidic, I will try this experiment again.

[Edited on 9-10-2025 by Romix]

chempyre235 - 9-10-2025 at 11:33

@Romix: In the picture you posted, it appears that you'd started to dissolve circuit boards in the solution. Was this after the tin, or was it your source of tin?

Romix - 9-10-2025 at 11:47

Quote: Originally posted by chempyre235  
@Romix: In the picture you posted, it appears that you'd started to dissolve circuit boards in the solution. Was this after the tin, or was it your source of tin?

Source of tin.

bnull - 9-10-2025 at 12:24

Quote:
Source of tin.

Source of tin and lead, you mean.

chempyre235 - 9-10-2025 at 12:28

And probably several other metals.

Romix - 9-10-2025 at 12:39

Quote: Originally posted by bnull  
Quote:
Source of tin.

Source of tin and lead, you mean.

No, lead free solder used on PCBs.

bnull - 9-10-2025 at 12:43

Source of tin and silver, then. But remember that not every PCB uses lead free solder, what with those damned whiskers and all.

Romix - 9-10-2025 at 12:44

Quote: Originally posted by chempyre235  
And probably several other metals.

No, only Tin able to displace in these.

bnull - 9-10-2025 at 12:45

How did you make the nitrate? Acid plus copper?

Romix - 9-10-2025 at 12:51

Quote: Originally posted by bnull  
How did you make the nitrate? Acid plus copper?
3% nitric + Copper, correct.

pesco - 10-1-2026 at 07:42

Thanks Romix, That is an excellent idea !

I will soon try to "de-tin" pcb's with ZnNO3. Any possible base metals would not displace it like they would with Cu(NO3)2
It should be less work than using HCl and if the ZnNO3 is essentially a catalyst that means no losses.
I remember dealing with stannic acid before ad it was a PITA to filter, but never tried to improve the process as it was just incidental need. Maybe decantation would work or boiling it would firm up the precipitate to ease filtering.

Anyone here had more experience with stannic acid precipitate?

Romix - 21-2-2026 at 21:15

Quote: Originally posted by pesco  
Thanks Romix, That is an excellent idea !

I will soon try to "de-tin" pcb's with ZnNO3. Any possible base metals would not displace it like they would with Cu(NO3)2
It should be less work than using HCl and if the ZnNO3 is essentially a catalyst that means no losses.
I remember dealing with stannic acid before ad it was a PITA to filter, but never tried to improve the process as it was just incidental need. Maybe decantation would work or boiling it would firm up the precipitate to ease filtering.

Anyone here had more experience with stannic acid precipitate?


Please let me know how it goes, if Tin reacts into stannic acid on contact with aqueous ZnNO3.

[Edited on 22-2-2026 by Romix]

Romix - 22-2-2026 at 05:05

Never tried coagulating Stannic acid by boiling it, might work, might not.