vampirexevipex - 19-5-2012 at 17:37
Hello i recently electrolyzed a saturated solution of calcium acetate, and i noticed it change from Base to Acid. So since i don't know what reaction
happened (I cant find no info about it in the internet neither in the search engine) and im quite new at electrolysis, so can someone tell me whats
the solution and what happened at the anode and cathone?
bbartlog - 19-5-2012 at 18:00
Depending on conditions (current density, temperature, electrode materials) various things can happen at the anode when electrolyzing acetate
solutions. You can get ethane or oxygen, but also carbon dioxide. Is there a precipitate or cloudiness in your electrolyte? And how acid is it?
vampirexevipex - 19-5-2012 at 18:42
Theres no precipitate in the solution, from cloudy (normal aqueous calcium acetate), it is less cloudy than before (0.3 transparency), i used carbon
electrodes and the acidity is 6-6.8.
woelen - 20-5-2012 at 12:27
At the anode you most likely made some CO2 + CH3CH3. The CO2 makes the solution somewhat more acidic.
A side reaction will be formation of O2 and acid at the anode, making the solution also more acidic.
At the cathode you make Ca(OH)2 and with the CO2, which partly remains dissolved in the solution this make CaCO3.
If you want a more conclusive outcome, then I would suggest to wait, until the liquid is totally clear, before you start the electrolysis. Just allow
any cloudiness to settle at the bottom and then decant the clear liquid and use that for experiments. Then you probably notice formation of a white
precipitate on/around the cathode.
You also could add a few drops of dilute acetic acid to keep the liquid clear.