Give reasons: Concentrated $HNO_3$ can be transported in aluminium containers.

(N/A) $(i)$ Concentrated $HNO_3$ can be stored and transported in aluminium containers because it reacts with aluminium to form a thin,non-porous,protective oxide layer $(Al_2O_3)$ on the surface of the metal.
$(ii)$ This oxide layer makes the aluminium passive,preventing further reaction with the acid.
$(iii)$ The chemical reaction is: $2 Al_{(s)} + 6 HNO_{3(conc.)} \rightarrow Al_2O_{3(s)} + 6 NO_{2(g)} + 3 H_2O_{(l)}$