Silver baths: strike and analysis of silver

A. Hi Onur. Jason's posting is from 17 years ago; I would be surprised if he replies. However, did you try his advice that you check Perkin-Elmer for the calculation? Unfortunately I don't quite understand your question, but I see what looks to me like great info about this at www1.lasalle.edu/~prushan/Intrumental%20Analysis_files/AA-Perkin%20Elmer%20guide%20to%20all!.pdf

Luck & Regards,

A. Hi again, Onur. When we aren't told why you want to do something it is difficult to understand and answer properly, especially when we are obviously having some language difficulties :-(
But if your question is, "What is the percentage by weight of silver in silver cyanide", the answer can be found in the 2012-2013 Metal Finishing Guidebook, p. 863: AgCN is 80.5% silver. I.e., the weight of the silver cyanide is 1.242X the weight of silver.

Luck & Regards,

A. Hi again. If you have continuing questions post them. This is a public forum not a consulting service, and there are a thousand readers for every poster. It isn't fair to them to have them read the early entries on a discussion and then cut them out of the conversation further along :-)

Luck & Regards,

Hi again Furkan. Sara's posting was from 17 years ago as well, so I don't know if she will be responsive to questions -- but quizzing her on her qualifications doesn't seem like a promising way to try to re-engage her :-)
Sorry about your difficulties with this, but please either get someone at your school or company to help you "hands-on", or ask a specific question. In the context of atomic absorption analysis of silver, I don't know what the term 'currentless processes' even means. Apologies!
Thanks & Regards,


Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. The way I do it is as follows:

5.0 ml plating bath is combined with about 20 ml water in a 500 ml Erlenmayer flask, and about 3 ml 30% hydrogen peroxide added. Next, WAIT. In 10 - 15 minutes, there will be a very obvious reaction in which most of the cyanide is destroyed, leaving a gray black precipitate of silver metal/hydroxide.

Now, IN A FUME HOOD, add about 15 ml sulfuric acid and about 10 ml nitric acid,(cyanide gas will be evolved) and heat. First you'll see brown fumes, then the characteristic white fume of refluxing sulfuric. Heat it at this point until a clear solution is obtained. There is sometimes a little solid matter that will not dissolve. Let it cool.

Then, lastly, carefully add about 150 ml water, and about 1 ml of 5% ferric ammonium sulfate solution. Titrate to an orange-red endpoint with 0.1 N potassium thiocyanate solution.

ml titrated x 0.288 = Silver in oz/gal (avoir)

Good luck!

A. Why not use atomic absorption spectrophotometry? in a 100 ml volumetric flask, dilute your sample 10:100, then add 1 ml to each flask, marked a, b, c ... in flask b spike with 1 ml of 100 ppm silver reference, in flask b spike with 2 mls 100 ppm silver reference solution, run on AA with silver lamp and proper wavelength and slit; you will record the results of each flask (a, b, and c) I'm afraid I do not have the calculations with me offhand for the results, but they are available from perkin-elmer.

A. Concentration of silver strike should be 1.5 g/k AgCN + 100 g/l KCN.
15 minutes is too long!