Electrolysis mystery

[pickle_64]

Main Question or Discussion Point

Hi,
i recently constructed a hofmann apparatus at home out of pvc and had some trouble with it. Basically, once it is set up, i only get gas from one electrode, the other does nothing. H2SO4 is used as the electrolyte, and the is 12 volts at 4 amps being put through it, DC. are there any simple flaws i am over looking as i just want to keep the oxygen and hydrogen separate.

thanks, your help is greatly appreciated.

 

[Borek]

What are your electrodes made off? Prehaps you have evolving gas on one side and you dissolve electrode on the second?

 

[pickle_64]

copper sheet metal in a coil.

 

[Borek]

Very likely that you are dissolving copper. If so, solution will become bluish.

 

[pickle_64]

why would this stop the 2nd gas being released?

 

[Borek]

More or less you have

Cu -> Cu²⁺ + 2e

oxidation reaction instead of

2H₂O -> O₂ + 4H⁺ + 4e

 

[pickle_64]

Thanks for that, i thought copper would have worked and no other site would tell me properly. on the subject, do you know of any suitable metals for use in this situation that wouldn't set me back a heap?

 

[Borek]

Unfortunately the best I can think off is oplatinum - rather expensive. Carbon electrodes will be much cheaper, but don't ask me about details, as I don't know too much about them.

 

[pickle_64]

thanks for the help