An electrolysis reaction: Silver electrode and cathode, Rochelle Salt solution

[JustinHall]

Hi

I'm new to the forum, so first I want to say hello to everyone.

I have been interested in Colloidal Silver lately, and I have produced it with electrolysis in distilled water with NaCl as an electrolyte. I have used a Silver electrode and cathode for both of these experiments.

I realized I had a batch of Rochelle Salt (Potasium Sodium Tartrate) and I decided to try using that in aqueous solution as an electrolyte to see what I would get.

With table salt I got a yellowish cloudy solution that I believe was Silver Chloride, however with Rochelle Salt I got a cloudy white solution, that I believe is Silver Tartrate C₄H₄Ag₂O₆ and MAYBE NaOH and KOH, but I've looked all over the internet to try to determine if this is the case, and I haven't had much luck.

I just wondered if anyone could help me figure out what I've got here. Thanks in advance for any help!

-Justin Hall

 

[chemisttree]

Isolate some of the white powder and leave it in the sun for a few hours. If it changes color, it's silver-something, very likely silver tartrate. You might see if it dissolves in aqueous ammonium hydroxide and check the optical rotation of the solution to confirm tartrate.

 

[JustinHall]

Ok, thanks for the help. It will probably take quite a while to evaporate the solution as it is mainly water, but maybe I can check the optical rotation while it is still in solution. I have noticed that when I have the liquid in a dark room and shine a light through it the beam of light shifts red as it passes through more and more solution.

At any rate, thanks for the advice, I'll be sure to post my results, even if I have to wait a few weeks for the water to evaporate from the solution.

 

[JustinHall]

I just wanted to let anyone concerned know that this reaction appears to have been successful. As the water evaporated much of the eggshell colored suspension fell out of suspension and collected at the bottom of the dish I was desiccating it in. Once it had all collected at the bottom of the container, I placed the dish outside and I let the sun strike it for a while. I came back a couple hours later and it was a very dark, almost black grey color.

It appears I was able to synthesize a photoreactive silver salt from electrolysis with silver anode and cathode in a rochelle salt solution. I am pretty sure it's Silver Tartrate, but it's hard to be 100% certain, as there are other photoreactive silver salts. I don't think it was silver nitrate because I didn't use nitric acid, and the only source of nitrogen would have been the air in contact with the solution.

I'll post an update if I am able to determine positively that I created C₄H₄Ag₂O₆, but I'm pretty sure that's what I got.

 

[LudusRex]

Hello Justin,

It's great to see your interest in colloidal silver and your experimentation with different electrolytes. I can confirm that the cloudy white solution you obtained with Rochelle Salt is indeed silver tartrate (C4H4Ag2O6). This compound forms when silver ions (Ag+) from the silver electrode react with the tartrate ions (C4H4O6^-2) from the Rochelle Salt.

In addition to silver tartrate, you may also have some sodium hydroxide (NaOH) and potassium hydroxide (KOH) in your solution. These compounds are formed from the dissociation of the sodium and potassium ions in the Rochelle Salt. However, the amount of these hydroxides present will depend on the concentration of your Rochelle Salt solution.

I hope this helps clarify your results. Keep up the experimentation and don't hesitate to reach out with any further questions. Happy researching!

Best,