Calculate the standard reduction potential for the reaction that coverts Cu3+ to Cu2+. Cu3+ + 2e-> Cu+ E0 =1.28 V
Cu2+ + e-> Cu+ E0 = 0.15V
Add -nFEo for Cu^3+ + 2e ==> Cu^+
to -nFEo for Cu^+ ==> Cu^2+ + e
Then total = -nFEo. Solve for Eo
I ran through it quickly and if I didn't punch in the wrong numbers it's about +2.5 v for Cu^3+ + e ==> Cu^2+
To calculate the standard reduction potential for the reaction that converts Cu3+ to Cu2+, you need to subtract the reduction potentials of the half-reactions involved.
The given half-reactions are:
1) Cu3+ + 2e- → Cu+ with E° = 1.28 V
2) Cu2+ + e- → Cu+ with E° = 0.15 V
In the given half-reactions, the Cu+ ion is the common species. To combine the two reactions and cancel out the Cu+ ion, you need to multiply the second half-reaction by 2. This is done to balance the number of electrons in both reactions before adding them:
2Cu2+ + 2e- → 2Cu+ with E° = 0.15 V
Now, you can add the two half-reactions together:
Cu3+ + 2e- → Cu+ with E° = 1.28 V
2Cu2+ + 2e- → 2Cu+ with E° = 0.15 V
_____________________________________
Cu3+ + Cu2+ → 3Cu+ with E° = ?
The next step is to add the reduction potentials of the half-reactions to get the overall reduction potential:
E° (overall) = E° (Cu3+ → Cu+) + E° (2Cu2+ → 2Cu+)
E° (overall) = 1.28 V + 0.15 V
E° (overall) = 1.43 V
Therefore, the standard reduction potential for the reaction that converts Cu3+ to Cu2+ is 1.43 V.