Question

According to the molecular orbital theory, for $C{O}^{+}$:

• A. The bond order is less than that of $CO$ and $C{O}^{+}$ is paramagnetic
• B. The bond order is more than that of $CO$ and $C{O}^{+}$ is paramagnetic while $CO$ is diamagnetic
• C. The bond order is less than that of CO and $C{O}^{+}$ is diamagnetic
• D. The bond order is more than that of CO and $C{O}^{+}$ is diamagnetic while CO is paramagnetic

Answer 1

The correct option is B The bond order is more than that of $CO$ and $C{O}^{+}$ is paramagnetic while $CO$ is diamagnetic

The molecular orbitals of $CO$:$\sigma 1s^2{\sigma }^{\ast }1s^2\sigma 2s^2\pi 2p_y^2=\pi 2p_x^2\sigma 2p_z^2{\sigma }^{\ast }2s^2$

The bond order of $C{O}^{+}$ is more than 3 while the bond order of $CO$ equals 3. This is because the electron is taken from an antibonding orbital. The molecule is paramagnetic because of the unpaired electron in the ${\sigma }^{\ast }2s$ orbital.