Question

Why concentrated HNO3 can be transported in aluminium container

Answer 1

concentated HNO3 renders Al passive due to the formation of thin oxide coating on the surface of the metal which prevents further reaction. therefore conc HNO3 can be transported in Al containers.

Answer 2

Concentrated $\mathrm{HNO}_{3}$ can be transported into aluminium containers because concentrated nitric acid reacts with aluminium to form a protective layer of an oxide $\bold{\mathrm{Al}_{2} \mathrm{O}_{3}}$.

This protective layer of the oxide makes the aluminium unreactive and renders it be passive. This unreactive aluminium cannot react with $\mathrm{HNO}_{3}$ and therefore there are no further chemical reactions.

This makes it easy for aluminium to be stored and transported safely in aluminium containers.