It's pretty simple. The potassium metal created at the interface between the electrolyte and the Hg cathode is amalgamated and drops below the suface where it is protected from oxidation. As you say you want a turnover of the potassium back into the electrolyte, you would want to avoid agitating the mercury. In fact, you might want to try amalgamating the surface of a copper plate to use as a cathode, thus avoiding the issue of agitation altogether.
Something else you could try is to use whatever cathode you have now and cover it with a protective hydophyllic polymer such as polyvinyl pyrrolidone. I'm not sure how well this would work. It's just a guess. M. =========================================== --- On Sat 01/29, Robin van Spaandonk < [EMAIL PROTECTED] > wrote: In reply to Michael Foster's message of Sat, 29 Jan 2005 19:30:52 -0500: Hi Michael, [snip] > >I hate to suggest this in an era of hyperhysteria about >toxic substances, but a mercury cathode would likely >do the trick here. You just have a shallow layer of >Hg at the bottom of your cell and make sure the wire >that passes through the electrolyte to the the Hg is >insulated. If you are careful, you can stir the >electrolyte without disturbing the surface of the Hg >cathode. This is interesting, but I don't understand the reason behind the suggestion. Could you please explain? Regards, Robin van Spaandonk _______________________________________________ Join Excite! - http://www.excite.com The most personalized portal on the Web!
