Question

The decreasing order of the O – O bond order in O₂, O₂[AsF₆], KO₂.

(A) O₂[AsF₆] > O₂ > KO₂

(B) O₂ > KO₂ > O₂[AsF₆]

(C) O₂ > O₂[AsF₆] > KO₂

(D) O₂[AsF₆] > KO₂ > O₂

Answer 1

Correct option is (A) O₂[AsF₆] > O₂ > KO₂

Bond length ∝ 1​/Bond order

In K(O₂​) or O₂^−​, bond order is 1.5.

In O₂​, bond order is 2.

In O₂​(AsF₆​) or O₂⁺​, bond order is 2.5. 

Hence, the correct order is O₂​(AsF₆​) < O₂ ​< KO₂​.