Hacker News Reader

Comment by NotYourLawyer | Hacker News Reader

Yes.

There are likely other things you could observe by electrolyzing some convenient substance with just about any wire. But be careful — some electrolysis products are pretty nasty. Producing chlorine gas, for example, is straightforward.

If you have a salted potato (rescued from a salad perhaps), I would not do the experiment indoors, nor would I stick my face close to it.

Sheesh. You are not going to make enough of anything this way to hurt a termite, much less a human.

There are ways to kill someone with potatoes, but they don't involve electrolysis.

“There are ways to kill someone with potatoes” with no further explanation than a counter example is probably my favorite thing I’ve read today.

The preferred method seems to be to fry the potatoes in hot grease, then salt the hell out of them. Unsuspecting humans readily gobble these up. With repeated application, death by cardiovascular disease follows within decades.

Apparently potato salad is an almost perfect bacterial growth medium - a few hours can lead to rapid proliferation.

All one needs is two tea bags and some wax paper!

Did someone said about The Great Potato Cannon?

You can easily injure yourself with a 12V power supply, some wire, and some salt water. You can chlorinate an entire swimming pool with a power supply smaller than the average workstation’s and an appropriate electrolytic cell.

You can easily injure yourself with a 12V power supply, some wire, and some salt water

How, without breaking the skin?

I suppose you could burn yourself if you deliberately wrapped the wires around an appendage and immersed it in the salt water. It'd take a lot of current, and whether that would do more harm than just drinking the salt water is questionable.

Think chemical injury, not electrical injury. If you stick a pair of wires in salt water and supply a few volts (12V is more than enough — it’s enough overpotential to get lots of reactions going quickly), you will see:

The cathode reduces H+ to H2. Hydrogen gas is mostly harmless if breathed, but if you collect it, it’s explosive.

Water minus that H+ that turned into hydrogen gas leaves OH- behind. Concentrate that enough and you have a base that will dissolve your skin.

The anode can oxidize water to oxygen, which can be a fire or explosion hazard but is otherwise fine. (A stoichiometric mixture of hydrogen and oxygen is Bad News.) But this is not the major reaction because…

The anode can also oxidize Cl- (the chloride in your salt) to Cl2: chlorine gas. In the absence of considerable care (which you don’t have in this hypothetical potato salad or glass of saltwater), that chlorine gas will bubble right out of your little reaction, where it will end up in your eyes or your airways. And it will dissolve into your tears or the fluids in your airways and chlorinate you. You do not want do this. NIOSH says that chlorine gas is immediately dangerous to life and heath at 10 ppm, and you can easily achieve that in a cup with a little power supply. (Like I said, a hundred watts or so can chlorinate an entire swimming pool. Chlorinating your cornea is trivial in comparison.)

This is a major industrial process, which you should not do in your house:

https://en.m.wikipedia.org/wiki/Chloralkali_process

(Shrug) Unless you deliberately set up an industrial- or large-lab scale electrolysis rig, you will get more chlorine in your face by opening a bottle of bleach. Try it.

Reply on news.ycombinator.com