April 25, 2024, 04:55:11 AM
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Topic: Question of products of electrolysis using two stainless steel rods+saltwater  (Read 2768 times)

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Offline Katsurao

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Like I've said in my previous posts, I'm pretty new to chemistry, and I thought I'd try electrolysis.

I tried to synthesize NaOH by electrolyzing a saline solution using two stainless steel rods from a blow dart set, since I don't have any carbon rods. The top of the solution gradually became yellow, leading me to think it was chlorine, but as I looked closer, I noticed that it was the liquid itself. Then, the space between the two rods(closer to the rod with no bubbles) started forming a green compound. Soon after, The water below it near the middle became a brownish color, then soon after that, it became a orange color. And finally, a brown substance formed at the bottom, despite still having the same exact colors as previously mentioned. No visible chlorine has been released, and no gas has passed (or has seemed to pass)into the tube I have connected to the bottle.

Any ideas what the products are? I have linked a photo of the bottle; thank you for any feedback in advance!

http://imgur.com/ZYTDgyU

Offline Zyklonb

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The yellow solution was due to iron+3 ions from the dissolving stainless.
SS won't work as an anode (+) but will work fine as a cathode (-).
The green was nickle+2, which is visible only near the anode, before the iron (III) chloride drowns out the color.
The orange color, brown color and percipitate were all iron (III) hydroxide which percipitated from any hydroxide ions in solution. This was probably contamiated with nickle and chromium hydroxide as well.

You can't make sodium hydroxide without a salt bridge or membrane!
« Last Edit: January 09, 2015, 07:36:32 PM by Zyklonb »

Offline Enthalpy

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NaCl aqueous electrolysis produces hypochlorite, the swimming-pool odour. Chlorine production needs special measures (and precautions).

Very few (and expensive) metals fit as electrodes, especially if you expect chlorine. Stainless looks bad. You find graphite rods in 1.5V and 4.5V batteries; mind your fingers, as their contents is corrosive.

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