3B 3 Reduction potential lists

Question one of two

Type the species from the list provided which...

You cannot type superscripts and subscripts, so don't bother. To enter NH4+, simply type NH4+.

Reduction potentials

E°(Cr2O72-, Cr3+) = 1.33 V
E°(Hg2+/Hg) = 0.85 V
E°(Fe3+, Fe2+) = 0.77 V
E°(I2, I-) = 0.54 V
E°(S/S2-) = -0.48 V
E°([Zn(NH3)4]2+/Zn) = -1.04 V