Question

When $O_2$ is converted into $O_2^{+}$

• A. both paramagnetic character and bond order increase
• B. bond order decreases
• C. paramagnetic character increases
• D. paramagnetic character decreases and the bond order increases

Answer 1

Answer: (D)

(i) $O_2-(\sigma 1s{)}^2{\left({\sigma }^{\ast }1s\right)}^2(\sigma 2s{)}^2{\left({\sigma }^{\star }2s\right)}^2$

${\left(\sigma 2p_z\right)}^2{\left(\pi 2p_x\right)}^2{\left(\pi 2p_y\right)}^2{\left(\pi \ast 2p_x\right)}^1$

${\left({\pi }^{\star }2p_y\right)}^1$

Bond order $=\frac{N_b-N_a}{2}$

$=\frac{8-4}{2}$

$=2$

$O_2$ molecule having 2 unpaired electron.

(ii) $O_2^{+}-(\sigma 1s{)}^2{\left({\sigma }^{\star }1s\right)}^2(\sigma 2s{)}^2{\left({\sigma }^{\star }2s\right)}^2$

${\left(\sigma 2p_z\right)}^2{\left(\pi 2p_x\right)}^2{\left(\pi 2p_y\right)}^2{\left({\pi }^{\star }2p_x\right)}^1$

${\left({\pi }^{\ast }2p_y\right)}^0$

Bond order $=\frac{8-3}{2}$

$=2.5$

$O_2^{+}$ ion having only 1 unpaired electron.

Hence, when $O_2$ is converted into $O_2^{+}$ paramagnetic character decrease and the bond order increases.