Question

What product is formed when aluminum metal is treated with concentrated nitric acid?

• A. $Al(N{O}_3{)}_3$
• B. $Al(N{O}_2{)}_3+H_2$
• C. $A{l}_2{O}_3$
• D. $A{l}_4{O}_3$

Answer 1

The correct option is C $A{l}_2{O}_3$

Some metals ​(example: $Cr,Al$) do not dissolve in concentrated nitric acid​ because of the formation​ of a passive film of oxide on the surface​.
Hence, the compound formed is $A{l}_2{O}_3$ i.e. aluminum (III) oxide.