13enigma
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question about no electrolyte in electrolytic process
There are videos on YouTube of people doing electrolysis without any electrolyte. They use metal electrodes that are relatively close to each other
and when they turn on their power source the solution starts to fizz like if it had any electrolyte. How is this possible? What is the mathematical
way of writing these reactions down If distilled water and copper electrodes are used? And will some copper deposit in the solution?
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gdflp
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4-6-2017 at 08:32 |
Sulaiman
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Water is the electrolyte
If you start with completely pure H2O and any metal (that I can think of) electrodes,
when a potential difference (voltage) is applied across the electrodes a small current will flow as water is not a perfect insulator,
some of the H2O molecules autodissociate (break apart by themselves) to form ions, that can carry electrical charge from one electrode to
the other
https://en.wikipedia.org/wiki/Self-ionization_of_water
and
most metals (and most things in this universe) dissolve a little in water to produce metalic ions that can transport electrical charge between
electrodes
and
once the current starts flowing many many more metal ions enter the water, making it more and more conductive.
e.g. I first noticed this effect when I had pure (99.99%) silver wire as anode and cathode in pure distilled polished water,
impossible for me to measure the cell d.c. resistance because as soon as a voltage is applied, ionisation occurs and the resistance drops rapidly.
Water is the most amazing chemical that I have read about
https://en.wikipedia.org/wiki/Properties_of_water
https://en.wikipedia.org/wiki/Solvation_shell
CAUTION : Hobby Chemist, not Professional or even Amateur
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13enigma
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Quote: Originally posted by Sulaiman  | If you start with completely pure H2O and any metal (that I can think of) electrodes,
when a potential difference (voltage) is applied across the electrodes a small current will flow as water is not a perfect insulator,
some of the H2O molecules autodissociate (break apart by themselves) to form ions, that can carry electrical charge from one electrode to
the other
https://en.wikipedia.org/wiki/Self-ionization_of_water
and
most metals (and most things in this universe) dissolve a little in water to produce metalic ions that can transport electrical charge between
electrodes
and
once the current starts flowing many many more metal ions enter the water, making it more and more conductive.
e.g. I first noticed this effect when I had pure (99.99%) silver wire as anode and cathode in pure distilled polished water,
impossible for me to measure the cell d.c. resistance because as soon as a voltage is applied, ionisation occurs and the resistance drops rapidly.
Water is the most amazing chemical that I have read about
https://en.wikipedia.org/wiki/Properties_of_water
https://en.wikipedia.org/wiki/Solvation_shell
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Amazing. So when you used the silver electrodes in the distilled water, what happened? I mean like how many grams of silver deposited in the solution,
and how did the wires corrode quickly?
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Sulaiman
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The aim of that cell was to produce ionic/colloidal silver solution for ingestion and mouthwash.
I only ran enough coulombs through the cell to produce about 16 ppm silver in suspension,
(greater concentration leads to precipitation)
the silver wires had a little 'greyness' covering the anode,
(possibly a little silver oxide ?) and the wires were both dull after running the cell
(at less than 1 mA for many hours)
I did not weigh the loss of electrode material (silver) as I was not expecting a measurable change.
I wanted to measure the resistance of the cell just for its own sake, to understand the process a little better,
but even with a digital multimeter using the Ohms ranges, it was impossible to get a sensible resistance measurement,
the resistance plummets in seconds of voltage being applied.
CAUTION : Hobby Chemist, not Professional or even Amateur
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13enigma
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| Quote: Originally posted by Sulaiman | The aim of that cell was to produce ionic/colloidal silver solution for ingestion and mouthwash.
I only ran enough coulombs through the cell to produce about 16 ppm silver in suspension,
(greater concentration leads to precipitation)
the silver wires had a little 'greyness' covering the anode,
(possibly a little silver oxide ?) and the wires were both dull after running the cell
(at less than 1 mA for many hours)
I did not weigh the loss of electrode material (silver) as I was not expecting a measurable change.
I wanted to measure the resistance of the cell just for its own sake, to understand the process a little better,
but even with a digital multimeter using the Ohms ranges, it was impossible to get a sensible resistance measurement,
the resistance plummets in seconds of voltage being applied. |
This interesting. I always wondered how many times one can use a silver or copper electrodes before they "run out" of the molecules contained in them.
Right now I'm just trying to produce silver clumps or mud slime in the solution so that I could later add that into nitrate and create silver nitrate.
I want to make silver crystals once I have the silver nitrate. I know I can get it online but I don't want that. I just don't want to end up messing a
dull and completely gone electrodes. Usually in the past I used NaCl. The silver wire lost a 2 grams but the solution always contained more than that.
How is that possible?
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j_sum1
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| Quote: Originally posted by 13enigma |
This interesting. I always wondered how many times one can use a silver or copper electrodes before they "run out" of the molecules contained in them.
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Look up Faraday's laws of electrolysis. When you know what is happening, Faraday tells you how much and how fast.
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13enigma
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| Quote: Originally posted by j_sum1 | | Quote: Originally posted by 13enigma |
This interesting. I always wondered how many times one can use a silver or copper electrodes before they "run out" of the molecules contained in them.
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Look up Faraday's laws of electrolysis. When you know what is happening, Faraday tells you how much and how fast. |
What do you think about the 2 grams being lost? From the electrode that produce more than 2 grans to the solution
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