Question

The magnetic moment of superoxide ion is:

• A. $\sqrt{3}BM$
• B. $\sqrt{2}BM$
• C. $\sqrt{10}BM$
• D. $\sqrt{6}BM$

Answer 1

The correct option is A $\sqrt{3}BM$

Number of electrons in bonding molecular orbitals, $N_B=10$.
Number of electrons in anti-bonding molecular orbitals, $N_A=7$.
Number of bonds $=\frac{N_B-N_A}{2}=\frac{10-7}{2}=\mathrm{1.5.}$
Number of unpaired electron in case of superoxide $\left(N\right)=1.$ (See the diagram, also 1s orbital has not been shown in the diagram.)
Thus, magnetic moment $=\sqrt{N(N+2)}BM$$=\sqrt{3}BM.$