The corrosion of iron can be thought of as an electrochemical cell reaction. Calculate the voltage difference between two points of corroding iron differing only in their partial pressures of oxygen: 0.20 atm of oxygen at one point and 0.0010 atm of oxygen at the other. The reaction is: H2O + Fe (s) + 1/2 O2 (g) -- Fe(OH)2 (s)

Question

The corrosion of iron can be thought of as an electrochemical cell reaction.  Calculate the voltage difference between two points of corroding iron differing only in their partial pressures of oxygen: 0.20 atm of oxygen at one point and 0.0010 atm of oxygen at the other.  The reaction is: H2O + Fe (s) + 1/2 O2 (g) --> Fe(OH)2 (s)

DrBob222 · Answer

E_cell = E^o_cell - (0.0592/n)*log (more dilute soln/more concd soln).

E^o_cell = 0 since the two electrodes are the same; i.e, this is a concentration cell.
I would plug in 0.001 for more dilute solution and 0.20 for the more concentrated solution and calculate E. I believe n=2.
Check my thinking.