For the following metal couples, indicate which will be the anode and cathode
respectively in an electrochemical cell. Write balanced equations for the
reactions, and calculate the electrode potential for the cell in each case, assuming
standard conditions. Note which metal will corrode if they are in contact in a
(a) Sn/Sn2+ and Cu/Cu2+
(b) Cd/Cd2+ and Ag/Ag+
(c) Sn/Sn2+ and Al/Al3+
(d) Ag/Ag+ and Cu/Cu2+
The Attempt at a Solution
Now if I look at my reduction potentials for (c) lets say, Sn/Sn2+ will have a potential of -0.14 V and Al/Al3+ has a potential of -1.66 V. From this I would say that Al would be the anode since it has the lower reducion potential. However, the half equation then becomes:
[tex]Al--> Al^3^+ + 3e^- [/tex]
This is the reverse reaction that appears in the standard reduction table so wouldn't the potential now be 1.66 V???
This would then lead to an Emf of the cell of
Where the c means cathode and the a means anode.
I would really appreciate if someone could just look over this one problem and tell me if I'm doing it correctly.