14.19

[Gianna Apoderado 1B]

In the calculation of the standard potential for the left (Metal) reduction, how come the sign of the Cu oxidation potential doesn't become negative?

Initially, I had:
E^o(left) = E^o(right) - E^o(cell) = -0.34 - 0.689 = -1.029

But when I checked the answer, it was -0.349, meaning the potential of the Cu oxidation was left positive.

[Matthew Lin 2C]

Because the equation is actually E(cell)= E(cathode) - E(anode)
Thus, E(cathode)= E(cell) + E(anode) = -0.689+0.34 = -0.349 V

Hope this helps!