Electrochemistry Silver Cell 5

[BGDOCK]

It’s was Martjn idea about testing rinse water . To be clear that’s the photo with the silver chloride , that was allowed to settled , decanted and stored in a larger container for later processing .

 

[BGDOCK]

Poured a couple of bars for practice , I can’t help it .
Thanks guys

 

[James Ball]

I washed my cement silver with boiling 10% sulfuric acid. I kept the acid supernatent to see if any silver sulfate formed. I added several drops of my silver nitrate electrolyte and got no precipitate. To verify that my silver nitrate was present, I added HCL to the solution. This time, as expected, I got a white precipitate when I added a few drops of my electrolyte.

I think your solution was contaminated with chloride, possibly from your distlled water that maybe not be distilled. Try adding some good silver nitrate solution to your distilled water and see if you see a precipitate.

I saw a You Tube video where a guy (omegageek64) washed his cement silver with either HCl or sulfuric acid. He added HCl to his sulfuric acid wash and it was cloudy. I added silver nitrate to my sulfuric acid wash and did not see a ppt. I should have seen excess sulfate around to make silver sulfate. I am not sure why I did not see a ppt. I think the correct test was adding HCL to the wash and seeing a ppt. I will be washing some more cement silver tomorrow and will test the sulfuric acid supernatent with HCl and a NaCl solution. I suspect I am getting some loss of silver but I am also loosing some copper as the solution is blue when I add the sulfuric acid. The initial wash of the cement silver is colorless and then turns blue with H2SO4 (10%).

 

[James Ball]

Dissolving KNO₃ in water will not make an appreciable amount of either KOH or HNO₃. It is the salt of a strong acid. Sigma sells high purity KNO₃
and the pH ranges from 5 - 8 https://www.sigmaaldrich.com/US/en/specification-sheet/SIGALD/12648

 

[BGDOCK]

1.)So if KNO3 is a salt would it make a good electrolyte ? Would it dissociate into K+ ions and NO3 ?

2.) AgNO3 +KNO3 > ?

---

 

[Yggdrasil]

1.)So if KNO3 is a salt would it make a good electrolyte ? Would it dissociate into K+ ions and NO3 ?

2.) AgNO3 +KNO3 > ?

---

It has been many discussions on poor mans Nitric here.
But to make that you need Sulfuric acid and said Nitrate and then freeze out as much salt as you can.
It will never be pure and it is considered not suitable for Silver.
Why do you ask?

 

[BGDOCK]

I’m not making poor man’s nitric I am asking what is the product of silver nitrate and potassium nitrate .
KNO3 is potassium nitrate
AgNO3 is silver nitrate
H2SO4 is sulfuric acid

 

[Yggdrasil]

I’m not making poor man’s nitric I am asking what is the product of silver nitrate and potassium nitrate .
KNO3 is potassium nitrate
AgNO3 is silver nitrate
H2SO4 is sulfuric acid

I can't see that it will give any specific product.
You will end up with a mixed salt solution, or a "dirty" electrolyte.
Why introduce foreign ions which has no function into your electrolyte if you do not need to.

 

[BGDOCK]

I picked this up from silver cell for dummies and was trying it out

 

[Muratthechemist]

Hello There,
As a silver refinery system producer, i want to give a some idea that we are use on our systems;
50g/L silver (directly gram calculation)
10 g/L Free Nitric Ions.

We have two way, first way is directly nitric acid addition. Second way is feeding with some nitric salts like KNO3, NaNO3. But sometimes, K or Na cames with silver. After melting process they will become light and create acidity on melting pot or area. Best way to addition Nitric acid.

Mole = mass / Molecule Weight ----- 10(g)/63,01 (mW) = 0,1587 Moles;
M1V1 = M2V2 ---- M1 is our stock solution it totally depends on percentage of producer. Industrial standarts are between 65-56%.
Lets say 65% HNO3 (KNO3 calculation is different but i also explain below)
To calculate per liter
15.86 (stock solution molarity) x Volume (that we need) = 0,1587 x 1000 (1L)
Volume (that we need) = 0,0101L (10 mL for Liter)
That is free nitric acid for preparing electrolyte solution.

For each liter you can add 10mL but during the process time, you should add maybe daily. Amper amounts will enlight you.
Amper efficient connected three things;
- Silver Ions (silver nitrate) in solution,
- Electrolyte quality (free nitrate ions) in solution,
- Connection strenght (some times copper cold oxides if open circuits.).
Once it reduce (it will reduce by anode consumes but it will be very small amounts day by day) we should strength again to get maximum efficiency.

Thank you for your patiente to read all of these..

 

[Yggdrasil]

I saw a You Tube video where a guy (omegageek64) washed his cement silver with either HCl or sulfuric acid. He added HCl to his sulfuric acid wash and it was cloudy. I added silver nitrate to my sulfuric acid wash and did not see a ppt. I should have seen excess sulfate around to make silver sulfate. I am not sure why I did not see a ppt. I think the correct test was adding HCL to the wash and seeing a ppt. I will be washing some more cement silver tomorrow and will test the sulfuric acid supernatent with HCl and a NaCl solution. I suspect I am getting some loss of silver but I am also loosing some copper as the solution is blue when I add the sulfuric acid. The initial wash of the cement silver is colorless and then turns blue with H2SO4 (10%).

The reason for the ppt when adding HCl to the Sulfuric is that the Silver Sulfate reacts and makes Silver Chloride.
When using Silver Nitrate you do not add Chloride ions and hence no Silver Chloride can form from the Sulfate and Nitrate.

 

[Yggdrasil]

I picked this up from silver cell for dummies and was trying it out

It will work, but you are adding foreign ions you do not need.
If you have access to Nitric there is no reason to use other.

 

[Muratthechemist]

So I finally used a 4L stainless steel bowl.
Silver crystals turned out ok
Heated the solution this time and added KNO3
How do you figure out the correct ratio of KNO3 to use ? I just added. Three tablespoons , next time i will give tartic acid a try.
Thanks

Regularly, 10g/L is sufficient;

KNO3 moleculer mass is : 101,1032 --- m = m / Mw --- 10 /101,1032 = 0,0989 moles.
K in KNO3 is 39,098, so ; 39,098 /101,1032 = 0,386 K+ , 0,614 NO3- = 1
0,614 (nitric only)*101,1032(total mw)= 62,077 NO3, 39.098 K
10/62,077= 0,1611 Moles of NO3 Also ;

10/0,614= 16,28 Grams of total KNO3 is contains 10g NO3- İons.

16,28g per liter.

 

[James Ball]

The reason for the ppt when adding HCl to the Sulfuric is that the Silver Sulfate reacts and makes Silver Chloride.
When using Silver Nitrate you do not add Chloride ions and hence no Silver Chloride can form from the Sulfate and Nitrate.

I agree. My test was inconclusive.

 

[James Ball]

The reason for the ppt when adding HCl to the Sulfuric is that the Silver Sulfate reacts and makes Silver Chloride.
When using Silver Nitrate you do not add Chloride ions and hence no Silver Chloride can form from the Sulfate and Nitrate.

I just got through washing about 8-900 g of cement silver with distilled water until the distilled water washes were colorless. I added 1 L of 10% v:v sulfuric acid and boiled it for an hour. My solution was deep blue. I think I maybe leaving my copper pipes in my silver nitrate solution too long and generating a copper contamination (CuO???) that is not washed out with distlled water.

I kept the sulfuric acid wash and one distilled water wash of the cement silver after decanting the 10% sulfuric acid solution. I combined the two samples, about 1.2L. I added 200 mL of concentrated HCl and saw NO ppt. Therefore no silver chloride formed from silver sulfate which would have happened if 10% sulfuric acid dissolved silver. I think 10% sulfuric acid is low enough in concentration that silver is not appreciably dissolved. At least my experiments suggest this.

 

[James Ball]

I’m not making poor man’s nitric I am asking what is the product of silver nitrate and potassium nitrate .
KNO3 is potassium nitrate
AgNO3 is silver nitrate
H2SO4 is sulfuric acid

There is no product from KNO₃ and AgNO₃; they do not react with each other. All you would have would be K⁺, Ag⁺and NO3^-ions dissociated in water.

 

[BGDOCK]

Thanks James