Question

Assertion $(A)$ Sodium reacts with oxygen to form $Na _{2} O _{2}$ but potassium reacts with oxygen to form $KO _{2}$.
Reason $(R)$ Potassium is more reactive metal than sodium.

• A. If both Assertion and Reason are true and Reason is 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: (B)

It is because of bigger size of $K ^{+}$than $Na ^{+}$, a weak positive field arises around it which cannot prevent peroxide ion $\left( O _{2}^{2-}\right)$ to combine with another oxygen atom to form superoxide, $O _{2}^{-}$.