Question

Assertion : Al becomes passive in conc. HNO₃.
Reason : Conc. HNO₃ has no action on aluminium metal.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (C)

Al metal is rendered passive when treated with conc. HNO₃ because concentrated HNO₃ is oxidising agent and produces a protective layer of oxide on the surface.