From: Stefan Trethan
> just a question: why the hell do you mention 6.3V exactly? seems
> too high for chem. voltage differential? which reason?
6.3VAC is a common transformer output voltage (e.g. see Radio Shack). Back in the days of carburetors, vinyl records, mechanical adding machines, and Elvis, vacuum tubes used 6.3V (or some multiple) on their filaments.
And why was that? I don't know for sure, but maybe that was the nominal voltage of 4 carbon-zinc cells in series.
The voltage times current = power which may do some chemical work, and the rest turns into heat. When doing electrolysis, bubbles tend to form on the electrodes and raise the resistance between the electrodes. Increasing the voltage would raise the temperature in that region and cause the bubbles to rise, increase the circulation of fluids, and increase the chemical reaction rates. (But whether it increases the rate of the reactions you _want_ is something I don't know. :-)
> some different thought:
> for a guy from mars, no chemical knoweledge, only common sense,
> woldn't it sound strange to etch kilos
> of plain copper away to get CuCl2 if he initialy only wants to
> etch copper? (sounds pretty much like
> digging a bigger hole to dump the earth of a hole you want to
> dig).
Heh. Again, it's the blind leading the blind here. But it sounds like the CuCl2 wants to take on another Cu (so it is an etchant), and CuCl2 doesn't release HCl gas into the air where it would corrode every metal object in your workshop, not to mention your eyes and lungs.
Cheers,
- Jan
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