Q4: Iron (d = 7.87 g/cm') corrodes in a deaerated solution of pH 2. The Fe activity in the solution is 10* M. The value of the cathodic, b., & anodic, ba, Tafel slopes are -0.16 & +0.15 V/decade, respectively. The exchange current density for iron & for hydrogen on iron is ia = 10-5 A/cm & i = 10-9 A/cm', respectively. Assume that the iron surface acts as cathode. Calculate the corrosion potential, the corrosion current density in A/em and the corrosion rate in gmd? t)