When electricity is applied to a molten binary salt, the cation will be reduced and the anion will be oxidized. The electrolysis of CaBr2(l), for example, produces Ca(s) at the cathode (from the reduction of Ca2+) and Br2(l) at the anode (from the oxidation of Br-).

If more than one cation is present, only the one with highest reduction potential will be reduced. Similarly, if more than one anion is present, only the one with the highest oxidation potential will be oxidized.

Electrolysis is performed on a mixture of CuBr(l), AgBr(l), MgBr2(l), and NiBr2(l). Which of the following is produced at the cathode?

a) Br2(l)
b) Cu(s)
c) Ag(s)
d) Mg(s)
e) Ni(s)