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Electrolysis, water, and various metals

  1. Aug 11, 2013 #1


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    I did an experiment, prompted by another thread, and saw something you kids probably see all the time:


    I was trying to measure the resistance of seawater, and came up with ≈11Ω. End of experiment, or so I thought......

    But then I decided that my battery voltage was a bit low and decided to charge it up properly with my 1200 watt charger.

    When I was doing this, I decided to do another experiment, and plunged the battery post sized alligator clips into the water for a moment, and saw that the electrolysis effect was about the same. meh. Nothing exciting there. So I went back to charging the battery.

    When I came out 30 minutes later, the water in my pyrex was rust colored, and there was a 1/4 inch precipitate of rust colored stuff at the bottom.

    I was once again puzzled, and did it again. I plunged the clips into my pseudo-ocean water, and several seconds later, the water turned almost black!

    That was a bit ago, and when I went out again, the rust had precipitated to both the top and bottom, there was a black film around the top, and the middle was semi-clear.

    I imagine that with chrome plated steel clips crimped to copper wiring attached to lead posts in an oxygen laden atmosphere, that the fluffy white stuff I saw disappear during this 2nd half of my experiment were some types of metal-oxides.


    Sorry for the rant, but if anyone knows why the water turned black, I won't have to google that in the morning.

  2. jcsd
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