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)

1.5

Answer 2

The $MO$ configuration of superoxide ion,

$(O^-_2 (8 + 8 + 1 =17) = \sigma1s^2 ,\overset{*}{\sigma} 1s^2 ,\sigma2s^2, \overset{*}{\sigma}2s^2 , \sigma 2p_z^2 \approx \pi 2p^2_y , \approx \pi 2p^2_y , \overset{*}{\pi} 2p^2_x \approx \overset{*}{\pi} 2p^1_y )$
$B.O = \frac {N_b -N_a}{2} = \frac {10 - 7}{2} = \frac {3}{2} = 1.5$