Write the reactions for the corrosion of iron $(Fe)$:
$(a)$ Oxidation of $Fe$.
$(b)$ Reduction of $O_2$.
$(c)$ Overall reaction of corrosion of $Fe$.

(N/A) The corrosion of iron is an electrochemical process occurring in the presence of moisture and oxygen.
$(a)$ At the anode,iron undergoes oxidation:
$2Fe(s) \rightarrow 2Fe^{2+}(aq) + 4e^-$
$(b)$ At the cathode,oxygen undergoes reduction in the presence of $H^+$ ions:
$O_2(g) + 4H^+(aq) + 4e^- \rightarrow 2H_2O(l)$
$(c)$ The overall reaction is obtained by adding the anodic and cathodic reactions:
$2Fe(s) + O_2(g) + 4H^+(aq) \rightarrow 2Fe^{2+}(aq) + 2H_2O(l)$