The bond order of O2+ is:

Explanation:

Total number of electrons in O₂ is 16

Total number of electrons in O₂⁺ is 15

M.O. configuration of O₂ ⁺

(σ1s)²σ∗(1s)²σ(2s)²σ∗(2s)²σ(2pz)²π(π2px)²π(2πy)²π∗(2pz)¹

Bond order = Nb − Na/2 = (10−5)/2 = 2.5

Final answer:

Correct option is C: 2.5