Couple Half-reaction E / V
Sn2+/Sn

Sn2+ + 2e¯ Sn

 −0.14
I2/I¯

I2 + 2e¯ 2I¯

 0.54
Ag+/Ag Ag+ + e¯ Ag 0.80
O2/H2O O2 + 4H+ + 4e¯ 2H2O 1.23

1. Deduce which of the following species is the strongest oxidant:
    I2, Ag+, Sn2+, O2

The strongest oxidant is dioxygen, O2, because it is lowest in the table,
or because it has the most positive electrode potential.