Electrolysis project thread

[BeaverRat]

That article is absolutely legit... I'm referring to the random article written by some random guy on some random website...

[saefroch]

Citric acid is a weak acid, as opposed to something like Hydrochloric acid, which is a strong acid.

[BeaverRat]

Citric acid would not pull enough amps if you used a proper voltage range of 1.4 to about 2.2 max.

[saefroch]

Citric acid would not pull enough amps if you used a proper voltage range of 1.4 to about 2.2 max.

It depends on the concentration. It's probably possible to drive the resistance of the solution down very far with a high concentration of citric acid. If you can do equilibrium chemistry, it's possible to calculate this.

[velocity3x]

I'm trying to not be rude, but......

GFYS. You're not trying hard enough.

[BeaverRat]

Citric acid would not pull enough amps if you used a proper voltage range of 1.4 to about 2.2 max.

It depends on the concentration. It's probably possible to drive the resistance of the solution down very far with a high concentration of citric acid. If you can do equilibrium chemistry, it's possible to calculate this.

True, but in my experimentation, I have always hit a point where adding more electrolyte failed to decrease resistance.

[Technician1002]

Anything that dissolves ionically in water can be used for electrolyte. Even table salt works well. The OP even mentioned it.

[Insomniac]

I believe the purpose of removing the chromium from the surface of the plates is simply that, normal use will cause the chromium to leech out so you may as well get as much out in one hit as you can, so that you arn't contaminating the water with chromium every time you use it. It makes disposal of the water much simpler and safer if it's not contaminated.

[saefroch]

I understand why one doesn't want chromium at all in an electrolysis apparatus, so why wouldn't one just use a steel without chromium in it in the first place?

[inonickname]

Because then you would have electrodes that would be lost and contaminate your electrolyte very quickly. I think the hexavalent chromium 'problem' is hugely overhyped in this circumstance. I don't think it's dangerous, but that said, I wouldn't drink the water, or tip it on anywhere where it could end up in drinking or plants you intend to eat.

[saefroch]

So if the chromium is completely removed from the surfaces of the plates, and it is still necessary, what is it doing? The only possible explanation I see for using an alloy with chromium in it (this is assuming, possibly incorrectly, that the only function of the chromium is to oxidize and prevent any other components from oxidizing) is that once the concentration at the surface of the electrode is low enough, it maintains some sort of equilibrium with the solution, but the solution is now in a lower concentration because of the change in the surface composition of the electrode.

Just from a bit of reading, I think chromium behaves in a very general sense, like arsenic. It masquerades as sulfur, like arsenic does phosphorous (SO4 is like CrO4, apparently), then causes problems later once it's been incorporated into biochemicals. However, according to Wikipedia, it only does this in the 6+ oxidation state. In a 3+ oxidation state it cannot be transported into cells, and is not nearly so dangerous. Looking up the oxidation potentials for chromium, expecting to fail.

[DYI]

There seems to be an awful lot of fuss over chromium VI in this thread. What are you doing with the gases you generate, making a deep-diving breathing mix?

[saefroch]

chromium VI

Wouldn't that be Chromium(VI)?

I am hoping to generate enough hydrogen to use it in a pneumatic. The apparatus might be a little fiddly, but unless you think you have a good idea for collecting the gas off only the anode, I'm going to start drawing up designs. Like this one, using PVC or some other plastic for the container: