Account for the following:
$(a)$ Aluminium is more reactive than iron,but its corrosion is less than iron.
$(b)$ Hydrogen gas is not evolved when zinc metal reacts with dilute $HNO_3$.
$(c)$ Carbon is not used for reducing aluminium from aluminium oxide.

(N/A) Aluminium forms a strong,non-porous,and protective layer of aluminium oxide $(Al_2O_3)$ on its surface upon exposure to air. This layer does not peel off easily and prevents further oxidation or corrosion of the underlying metal.
$(b)$ Dilute $HNO_3$ is a strong oxidising agent. When it reacts with metals like zinc,it oxidises the hydrogen gas produced during the reaction into water $(H_2O)$ and itself gets reduced to nitrogen oxides (such as $N_2O$,$NO$,or $NO_2$).
$(c)$ Aluminium has a much higher affinity for oxygen than carbon does. Therefore,carbon cannot effectively remove oxygen from aluminium oxide $(Al_2O_3)$ to produce aluminium metal. Consequently,electrolytic reduction is used instead of carbon reduction.