4. Iron corrodes in a sea water solution of pH 7. Assuming corrosion is activation controlled and proceeds by oxygen reduction, calculate the minimum current required for complete cathodic protection. Exchange current density, i0, for oxygen reduction is 107mA/cm2. Assume c=0.15V/ decade and Eeq,Fe=0.44V vs. SHE Hint: oxygen reduction standard equilibrium potential can be found in standard potential tables [4 pts]