Question #29891
Predict whether Fe3+ can oxidize I- to I 2 under standard-state conditions
Expert's answer
The appropriate half-reactions are
I2(s) + 2e− → 2I−(aq)
Eanode = 0.53V
Fe3+(aq) + e− → Fe2+(aq)
Ecathode = 0.77 V
Since Fe3+/Fe2+ is more positive, it should oxidize I– to I2. This makes the I2/I– half-reaction the anode. The standard emf can be found
Ecell = Ecathode − Eanode = 0.77 V − 0.53 V = 0.24 V
I2(s) + 2e− → 2I−(aq)
Eanode = 0.53V
Fe3+(aq) + e− → Fe2+(aq)
Ecathode = 0.77 V
Since Fe3+/Fe2+ is more positive, it should oxidize I– to I2. This makes the I2/I– half-reaction the anode. The standard emf can be found
Ecell = Ecathode − Eanode = 0.77 V − 0.53 V = 0.24 V
