What happens when you run house electricity (120VAC) through salt water? (with standard copper wires!)

Well, in https://youtu.be/dcrY59nGxBg , an interesting experiment was conducted to find out!

At the end of the video, however, I noticed the salt water became rather dark and murky, and I'm wondering what happened inside.

Did the copper wires just corrode into some kind of precipitate? $$\ce{Cu(s) + H2O(\ell) -> CuO(s) + H2(g)}$$ $$\ce{Cu(s) + 2H2O(\ell) -> Cu(OH)2(s) + H2(g)}$$

Was there chlorine gas even created too? $$\ce{2H+(aq) + 2Cl^{-}(aq) -> H2(g) + Cl2(g)}$$

  • 1
    $\begingroup$ Much of $\ce{Cu^2+}$ will initially go to the solution and only gradually form precipitate. Other than that, everything seems right. $\endgroup$ Commented Dec 23, 2019 at 14:20
  • 2
    $\begingroup$ Does this answer your question? Electrolysis puzzle $\endgroup$
    – Mithoron
    Commented Dec 24, 2019 at 0:13
  • 1
    $\begingroup$ chemistry.stackexchange.com/questions/49578/… $\endgroup$
    – Mithoron
    Commented Dec 24, 2019 at 0:14
  • $\begingroup$ @Mithoron Not quite, it seems those experiments were conducted under much milder/less extreme conditions, thus allowing other more gradual coloration effects to be demonstrated. Ivan Neretin's answer is spot on, pointing to the eventual result of running this setup to completion and likely accelerated by the large 120V supply. $\endgroup$
    – ManRow
    Commented Dec 24, 2019 at 1:32
  • $\begingroup$ On a side note, would it be a bad idea to just pour the final solution down the drain, as copper ions may be an environmental hazard? (The video did not demonstrate how it was disposed) $\endgroup$
    – ManRow
    Commented Dec 24, 2019 at 1:38


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