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6O.3a

Posted: Sat Feb 29, 2020 3:31 pm
by Alicia Lin 2F
For this question, if I choose the water reaction to occur at the cathode and the Mn2+ reaction to happen at the anode, wouldn't this yield a positive Ecell value? Since Ecell=-0.42V-(-1.18V)=+0.76V. But we are dealing with electrolytic cells which are supposed to be negative Ecell right? How does this make sense

Re: 6O.3a

Posted: Sat Feb 29, 2020 9:46 pm
by Chem_Mod
You are electrolyzing an aqueous solution of metal cations; you are not “choosing” per se what reduction half reaction occurs but figuring out which one will occur. Even if you run a current through the cell to allow the non-spontaneous reaction to occur, the two reduction half reactions are still competing with each other and the more favorable one will occur