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14.55

Posted: Thu Mar 15, 2018 2:35 am
by Janine Chan 2K
The solution manual states that the cathode should have the least negative E and the anode should have the most negative E. However, it then says that the cathode, which is Ni2+, has a E of -0.23 V while the anode has a E of +1.23 V. Isn't this contradictory?

Also, if the point is to make a cell with the least negative E, does this mean that the value of E must be negative (but just not very negative) or does it just mean we want the most positive value possible?

Re: 14.55

Posted: Thu Mar 15, 2018 9:49 pm
by Andy Nguyen 1A
The +1.23 volts is for the oxidation reaction. The standard reduction potential is actually -1.23 V so the solution manual is correct. And you want to get the most negative value of E because in an electrolytic cell, the reaction is non spontaneous.

Re: 14.55

Posted: Thu Mar 15, 2018 10:33 pm
by Janine Chan 2K
Andy Nguyen 1A wrote:The +1.23 volts is for the oxidation reaction. The standard reduction potential is actually -1.23 V so the solution manual is correct. And you want to get the most negative value of E because in an electrolytic cell, the reaction is non spontaneous.


Thanks, I see what you mean. But if the +1.23 volts is for the oxidation reaction (aka they already made it the negative of the standard reduction potential), the equation in part c should say -0.23 + 1.23, which should give a positive voltage, right?

Re: 14.55

Posted: Sat Mar 17, 2018 8:10 pm
by Andy Nguyen 1A
I believe you should get a positive voltage since the cell is electolytic.