Question

The calculated bond order of superoxide ion $(O_2^{-})$ is

• A. 2.5
• B. 2
• C. 1.5
• D. 1

Answer 1

Answer: (C)

The $MO$ configuration of superoxide ion,

$(O_2^{-}(8+8+1=17)=\sigma 1s^2,\stackrel{\ast }{\sigma }1s^2,\sigma 2s^2,\stackrel{\ast }{\sigma }2s^2,\sigma 2p_z^2\approx \pi 2p_y^2,\approx \pi 2p_y^2,\stackrel{\ast }{\pi }2p_x^2\approx \stackrel{\ast }{\pi }2p_y^1)$

$B.O=\frac{N_b-N_a}{2}=\frac{10-7}{2}=\frac{3}{2}=1.5$