5 ms·

Can anyone explain what's really happening here? Why green? Why potato?

DeIonizedPlasma 4y ago
Copper salts are green. The copper will only give up an electron and make itself available to form salts with the ions in the potato at the positive electrode. This should also work with anything else conductive, you'd probably be able to tell doing this in a glass of salt water provided that the water is still enough.
- eloff 4y ago
  So does this only work with copper wires then?
  - NotYourLawyer 4y ago
    Yes.
    - amluto 4y ago
      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.
      - CamperBob2 4y ago
        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.
        eyelidlessness 4y ago
        “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.
        greenbit 4y ago
        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.
        etrautmann 4y ago
        Apparently potato salad is an almost perfect bacterial growth medium - a few hours can lead to rapid proliferation.
        b112 4y ago
        All one needs is two tea bags and some wax paper!
        ProtoAES256 4y ago
        Did someone said about The Great Potato Cannon?
        KingLancelot 4y ago
        amluto 4y ago
        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.
        CamperBob2 4y ago
        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.
  - pipeline_peak 4y ago
    Potato
  - IndrekR 4y ago
    For other metals you can enjoy watching how one wire erodes away and other one stays nice and bright. Does not need to be potato either — any water based conductive medium will do. Even a cup of hard tap water is conductive enough. Distilled/RO/DI water will not conduct reasonably well. You can just add a drop of salt/vinegar/juice/etc to make it more conductive.
- Cyberdog 4y ago
  Copper salts are a start, but I think I'd prefer mine with copper pepper as well.
deleted 4y ago
[deleted]
_carbyau_ 4y ago
In a solution (or potato in this case) running electricity between two points will cause one point to lose material. So one wire will lose material into the potato. Assuming the wire is copper (much wire is) it will appear green in similar vein to how the statue of liberty is green.
nmeta 4y ago
I too was intrigued by this and did a quick google search. I came upon this which I think is a similar (if not the same) reaction as is occurring in OP. https://thehappyscientist.com/content/simple-electrolysis https://thehappyscientist.com/content/simple-electrolysis And in the final paragraph states that, and I'm loosely plagiarizing here, the negative ions created in an electrolysis reaction are attracted to the positive/live terminal*, and in the presence of chlorine (as in salts found in the potato) the copper (wiring) react to form green copper chloride. Edit: not battery, but positive/live terminal
- robocat 4y ago
  The way to remember it is that the negative ions of Chlorine Cl- move towards the positive wire electrode. At the copper wire of the positive electrode the chlorine reacts with the copper to make green hydrated copper(II) chloride - CuCl2·2H2O - https://en.m.wikipedia.org/wiki/Copper(II)_chloride https://en.m.wikipedia.org/wiki/Copper(II)_chloride
myself248 4y ago
Others have covered the copper angle. But it doesn't have to be a potato. A bit of paper towel moistened with salty water or saliva would also work, all you need is for current to flow initially (that's the purpose of the salt), and for something to carry the copper ions (the water).

Copper salts are green. The copper will only give up an electron and make itself available to form salts with the ions in the potato at the positive electrode. This should also work with anything else conductive, you'd probably be able to tell doing this in a glass of salt water provided that the water is still enough.

eloff 4y ago
So does this only work with copper wires then?
- NotYourLawyer 4y ago
  Yes.
  - amluto 4y ago
    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.
    - CamperBob2 4y ago
      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.
      - eyelidlessness 4y ago
        “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.
        greenbit 4y ago
        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.
      - etrautmann 4y ago
        Apparently potato salad is an almost perfect bacterial growth medium - a few hours can lead to rapid proliferation.
      - b112 4y ago
        All one needs is two tea bags and some wax paper!
      - ProtoAES256 4y ago
        Did someone said about The Great Potato Cannon?
        KingLancelot 4y ago
      - amluto 4y ago
        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.
        CamperBob2 4y ago
        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.
- pipeline_peak 4y ago
  Potato
- IndrekR 4y ago
  For other metals you can enjoy watching how one wire erodes away and other one stays nice and bright. Does not need to be potato either — any water based conductive medium will do. Even a cup of hard tap water is conductive enough. Distilled/RO/DI water will not conduct reasonably well. You can just add a drop of salt/vinegar/juice/etc to make it more conductive.
Cyberdog 4y ago
Copper salts are a start, but I think I'd prefer mine with copper pepper as well.

deleted 4y ago

[deleted]

_carbyau_ 4y ago

In a solution (or potato in this case) running electricity between two points will cause one point to lose material. So one wire will lose material into the potato. Assuming the wire is copper (much wire is) it will appear green in similar vein to how the statue of liberty is green.

nmeta 4y ago

I too was intrigued by this and did a quick google search. I came upon this which I think is a similar (if not the same) reaction as is occurring in OP. https://thehappyscientist.com/content/simple-electrolysis https://thehappyscientist.com/content/simple-electrolysis And in the final paragraph states that, and I'm loosely plagiarizing here, the negative ions created in an electrolysis reaction are attracted to the positive/live terminal*, and in the presence of chlorine (as in salts found in the potato) the copper (wiring) react to form green copper chloride. Edit: not battery, but positive/live terminal

robocat 4y ago
The way to remember it is that the negative ions of Chlorine Cl- move towards the positive wire electrode. At the copper wire of the positive electrode the chlorine reacts with the copper to make green hydrated copper(II) chloride - CuCl2·2H2O - https://en.m.wikipedia.org/wiki/Copper(II)_chloride https://en.m.wikipedia.org/wiki/Copper(II)_chloride

myself248 4y ago

Others have covered the copper angle. But it doesn't have to be a potato. A bit of paper towel moistened with salty water or saliva would also work, all you need is for current to flow initially (that's the purpose of the salt), and for something to carry the copper ions (the water).