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Author Topic: electrodes in salt water  (Read 1391 times)

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Lex Moen

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electrodes in salt water
« on: February 03, 2012, 01:39:38 AM »

I want to build a construction for the electrolysis of water (such as the Hofmann apparatus) but one that can work with salt water, sea water f.i. .what electrodes would be best to use in such an aggressive medium?
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Arkcon

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Re: electrodes in salt water
« Reply #1 on: February 03, 2012, 01:42:14 AM »

Platinum.  Hey, you said best.  You said nothing about cost effective.  Graphite electrode aren't bad.  But just about any electrode is prone to wear and tear, over the (very) long run.
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Lex Moen

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potential problem using platinum electrodes in sea water?
« Reply #2 on: February 03, 2012, 01:49:49 AM »

suppose I use platinum electrodes in seawater (hofmanns apparatus) . to electrolyse water.
do you think there is a risk of producing chlorine gas or other sideproducts?
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Arkcon

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Re: electrodes in salt water
« Reply #3 on: February 03, 2012, 01:54:00 AM »

Yes, if the electrolyte or other dissolved solids are chlorides then you will produce chlorine, and not oxygen.  The choice of electrode has no effect on this.

(and please don't create a new thread to followup the same question, it makes it hard for us all to see what's been said and to combine all our thoughts)
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That all depends on how reasonable we're all willing to be.  I just want my friends back, except for Cartman, you can keep him.

Lex Moen

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Re: electrodes in salt water
« Reply #4 on: February 03, 2012, 02:05:15 AM »

ok - sorry

so I produce chlorine. but at the other electrode, i do produce hydrogengas?
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vmelkon

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Re: electrodes in salt water
« Reply #5 on: February 03, 2012, 06:36:18 AM »

Yes, you get hydrogen at the negative electrode. You can use almost any conductor for the cathode and it won't degrade.
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billnotgatez

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Re: electrodes in salt water
« Reply #6 on: February 03, 2012, 06:53:28 AM »

There has been a discussion of this in the past and there is a belief that you are not limited to Chlorine at the positive electrode.

http://www.chemicalforums.com/index.php?topic=44669.0

I always thought you got Chlorine until the Sodium Chloride was depleted and then you would get Oxygen until the water is depleted.
But, if you peruse this forum you do not always get that as the answer.

In all cases of discussion I only say Hydrogen for the negative electrode.


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Lex Moen

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Re: electrodes in salt water
« Reply #7 on: February 03, 2012, 09:27:29 AM »

thanx, you were very helpfull and gave me usefull comments :-)
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