Question

Assertion :Reactivity of Al decreases if it is dipped in $HN{O}_3$. Reason: Nitric acid is a good oxidising agent, and so this causes a thickening of the oxide layer, further protecting the aluminium from reaction.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

Aluminium always has a strongly adherent coating of aluminium oxide which makes it appear much less reactive than might be expected from its position in the reactivity series. Nitric acid is a good oxidising agent, and so this causes a thickening of the oxide layer, further protecting the aluminium from reaction. Thus, due to the formation of a layer of oxide, i.e., $A{l}_2{O}_3$ , reactivity of Al decreases if it is dipped in $HN{O}_3$. Thus, both assertion and reason are correct and reason is the correct explanation for assertion to the solution