Consider the following half-cell reactions and associated standard half-cell potentials and determine the maximum voltage that can be obtained by combination resulting in spontaneous processes:
AuBr−4(aq)+3e−→Au(s)+4Br−(aq);E∘=−0.86 V
Eu3+(aq)+e−→Eu2+(aq);E∘=−0.43 V
Sn2+(aq)+2e−→Sn(s);E∘=−0.14 V
IO−(aq)+H2O(l)+2e−→I−(aq)+2OH−(aq);E∘=+0.49 V