Sciencemadness Discussion Board

electrolisys of H2SO4 makes ozone?

vmelkon - 13-8-2012 at 07:25

I used 2 lead electrodes dipped in 31% wt H2SO4 solution. I used 6 V, 1 A.
It is weird. I smelled ozone. I tried it multiple times the next few days and every single time, there was a strong smell of ozone. I though that oxygen is suppose to evolve from the anode but I guess a little ozone forms somehow.

Does anyone know anything about this?

And if no one knows, that's ok. It is new info for you.

[Edited on 13-8-2012 by vmelkon]

hissingnoise - 13-8-2012 at 07:48

Electrolytic ozone is well known and has a long history.
Useful quantities of ozone are produced using insoluble anodes.
Base-metals anodes produce negligible amounts of the gas!

AndersHoveland - 13-8-2012 at 17:57

Not really surprising. The electrolysis is probably producing some persulfate ions, which are are known to be able to decompose into ozone.
Quote:

By the thermal decomposition of the persulphates, small quantities of ozone can be obtained. 20 grams of dry freshly prepared ammonium persulfate are mixed with 15 gms. of nitric acid in a small flask. The air is subsequently displaced by carbon dioxide, and the mixture cautiously raised to 65° to 70° C. The reaction, which is strongly exothermic, proceeds somewhat vigorously when once started, and the resulting oxygen, after removal of the carbon dioxide, contains 3 to 5 per cent, of ozone and small quantities of nitrogen. Malaquin (" J. Pharm. Chem.," VII, 3, 329, 1911)


Production of persulfate by electrolysis of sulfate:
http://www.sciencemadness.org/talk/viewthread.php?tid=11022

vmelkon - 14-8-2012 at 09:14

Thanks for the responses.

AndersHoveland, the thread is interesting but there isn't any mention of ozone production.

For the thermal decomposition of a persulfate, yes, I was aware of that. You can also use sodium persulfate and a catalytic amount of H2SO4 to make oxygen and a little bit of ozone gets produced too when the persulfate is heated.