Sciencemadness Discussion Board

Galvanic cell reaction

Jose - 4-8-2018 at 09:56

I was reading about galvanic cells and reactions, and decided to buy a version with different metals and electrolyte. At the anode compartment I used Aluminum foil and NaCl anolyte and at the cathode I used tap water and copper cathode.

What I would expect to happen is that at the anode Aluminum will get oxidized as well as chloride ions, which would escape as chlorine gas. Some chlorine will dissolve back to make HClO and HCl, which will react with Al to make AlCl3 and maybe some NaClO. At the cathode oxygen will be reduced to OH and Na+ ions will migrate to the cathode to combine with OH to produce NaOH.

I used a carboard sallt bridge inside a plastic tube.

What do you think may happen?

AJKOER - 5-8-2018 at 17:27

Research Bleach battery on SM.

To your current setup add chlorine bleach.

chemack - 13-8-2018 at 04:35

Chloride on aluminum electrodes will not be oxidized: aluminum simply will not allow to raise the potential at the anode to the required values, it will dissolve at such a speed (potentials of these) at such a rate that nothing remains of the electrode at the moment. Such inorganic chemistry questions are often asked. You can try to experiment with the combined anode - graphite + aluminum. In the sediment (ideally, in the selection of parameters) there will be a gelatinous Al(OH)3, which has captured graphite particles and mechanical impurities from water, atomic oxygen, which oxidizes the organic matter and kills bacteria, will also be released. At the same time, chlorine and hypochlorite will hardly form, the water will turn out to be clean.