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Re: Electolysis of water

Ludwik Kowalski wrote:

electrolytic cell .... bubbles are coming out at some constant
temperature. I suspect that the second law can be used to determine
the ideal possible efficiency

The second law has little to do with it.
You should be able to come arbitrarily close
to reversibility, i.e. 100% efficiency.

B.C. wrote:

seems to me if one uses an electrolyte that has a high conductivity there will
be little Joule heating.

I dunno about that. Water is already 0.1 ppm auto-ionized,
(which you can raise to 1.0 ppm by heating the water)
and there's not much you can do to increase the diffusion
constant ... and beyond that, ISTM anything you do to
increase the nominal conductivity will _decrease_ the
efficiency, by conducting things that compete with the
reaction you're interested in.

The main thing is to put the minimal voltage across
the cell, just enough to cause the reaction to "turn on".
Anything above that is wasted for sure.

This posting is the position of the writer, not that of Sophocles,
Aristophanes, or Euripides.

This posting is the position of the writer, not that of SUNY-BSC, NAU or the AAPT.