Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: weebob on 18/09/2004 12:40:28

Title: Is electrolysis hindered by high pressure?
Post by: weebob on 18/09/2004 12:40:28

Hello There,

I was searching the other day and I came across this site

http://my.voyager.net/~jrrandall/BublGen.htm

and desalination by high pressure on the BBC

http://news.bbc.co.uk/2/hi/middle_east/3631964.stm

My question: Is Electrolysis of water hindered at high pressure ?







Bob

Title: Is electrolysis hindered by high pressure?
Post by: chris on 29/06/2008 23:01:30

This question looks really interesting - can someone please give a professional opinion, and also explain whether electrolysis occurs at the same rate irrespective of pressure?

Title: Is electrolysis hindered by high pressure?
Post by: Bored chemist on 30/06/2008 19:47:51

Electrolysis is pressure dependent.
For gases reacting at electrodes the pressure is (nearly) proportional to the concentration.
That concentration term apears in the Nernst equation.
http://en.wikipedia.org/wiki/Nernst_equation
Even a fairly moderate voltage can give rise to a high pressure.

Title: Is electrolysis hindered by high pressure?
Post by: chris on 30/06/2008 21:30:50

so if you pressurised an electrolysis vessel it would be possible to prevent the electrolysis from occurring?

Title: Is electrolysis hindered by high pressure?
Post by: Bored chemist on 01/07/2008 06:56:57

For a given voltage, yes. Raising the potential would get the reaction going again.

However I think that the original post is either trying to be a perpetual motion machine (in which case it won't work) or it's relying on the thermal gradient (the bottom of the ocean is cold) in which case there's probably a better way to extract energy from that thermal gradient.