Making gold plating solution from OTC chemicals.
Hi, everyone.
For the purpose of the experiment, I decided to make a gold plating solution with the chemicals I can purchase online. Even though I knew, it would be
more expensive than buying a professional gold plating kit.
Anyway, the first challenge is to get a reasonably concentrated nitric acid, as this chemical is restricted.
Lucky enough I had a soil pH down solution that I purchased a while ago. This solution is primary nitric acid at 30% concentration. I wasn't sure if
this strength was sufficient to make aqua regia and I concentrated the solution to 50%. I did it by fractions distillation. If you want to know more
details about it, you can watch my video.
https://www.youtube.com/watch?v=RLBfkEptr3s
Once I obtained nitric acid, I dissolved gold in aqua regia and evaporated the liquid at specific temperature until I was left with the red very
hygroscopic crystals of gold(III)chloride.
https://www.youtube.com/watch?v=DI3zt1oWU80
As a final step, I made a strongly alkaline solution of gold chloride and potassium ferrocyanide to produce gold plating electrolyte.
To see the process, and gold plating demonstrations, you can take a look at the video.
https://www.youtube.com/watch?v=Sr1bXJWKLf4
There isn't much information available regarding this process, so I had to collect bits from different sources. If I understand correctly, the
electrolyte contains gold cyanide as iron replaced by the gold ions in the cyanide ligands. During the electrolysis potassium cyanide forms in the
solution as gold deposits on the surface.
Please feel free to correct me if I made a mistake. I will appreciate it.
[Edited on 3-1-2017 by Ashot]
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