Question

Consider the following standard reduction potentials at 25oC in an aqueous acidic solution

E0 (V)
O2 (g) + 4 H+(aq) + 4 e- → 2 H2O(l) 1.229
Cl2 (g) + 2 e- → 2 Cl-(aq) 1.358
Ag+(aq) + e- → Ag(s) 0.800
Fe3+(aq) + e- → Fe2+(aq) 0.771
2 H+(aq) + 2 e- → H2 (g) 0
Fe2+(aq) + 2 e- → Fe(s) -0.440
Zn2+(aq) + 2 e- → Zn(s) -0.763

Find the standard reduction potential for Fe3+(aq) + 3e- → Fe(s)

Answer 1

Fe2+(aq) + 2 e- → Fe(s) -0.440
Fe3+(aq) + e- → Fe2+(aq) 0.771

multiply each potential by the number of electrons it's transferring, add them up, divide by the total number of electrons trasnfered

Answer 2

Is there a formula?

Answer 3

Nice, but what's the general formula?

Answer 4

i don't know if there is one, that slide is straight from my notes.

Answer 5

ok thanks