Chemical Forums

Chemistry Forums for Students => High School Chemistry Forum => Topic started by: gre on June 23, 2009, 12:39:04 PM

Title: Oxide build up on electrodes
Post by: gre on June 23, 2009, 12:39:04 PM

Hello,

While performing (8V) electrolysis on a cell constructed of concentric 316L stainless steel tube electrodes, I noticed a thick white layer had  formed on anode (outside electrode)  in the cell gap..  And on the inside of the cathode tube (inner electrode tube) there was a dark gray layer...   What are these layers exactly?

Thanks in advance.

Title: Re: Oxide build up on electrodes
Post by: Borek on June 23, 2009, 12:51:14 PM

Knowing electrolyte won't hurt...

But I doubt we will be able to help. Way too many possibilities.

Title: Re: Oxide build up on electrodes
Post by: gre on June 23, 2009, 05:48:36 PM

What are the variables?   Could it just be a 'cocktail' of oxides from the 316L composition?  I  was just using distilled water.

Title: Re: Oxide build up on electrodes
Post by: gre on June 24, 2009, 02:12:19 PM

Anyone?

Title: Re: Oxide build up on electrodes
Post by: gre on June 25, 2009, 12:06:58 PM

It seemed strange that a 'gray layer' would form on the inside of the cathode tube where current doesn't pass..   Is this normal?

Title: Re: Oxide build up on electrodes
Post by: gre on June 28, 2009, 12:47:15 AM

Could the gray layer be hexavalent chromium?