Question

$N_2$ and $O_2$ are converted into monocation , $N_2^{+}$ and $O_2^{-}$ respectively .Which of the following is wrong?

• A. In $N_2^{+},N-N$ bond weakens
• B. In $O_2^{-},O-O$ bond order increase
• C. In $O_2^2,O-O$ bond order decrease
• D. $N_2^{+}$ becomes paramegnetic

Answer 1

The correct option is B In $O_2^{-},O-O$ bond order increase

$N_2$ is diamagnetic as all the electrons are paired.
$N_2^{+}$ becomes paramagnetic as it contians one unpaired electron in $\pi 2p_z$ orbital.
The bond order decreases from $3$ to $2.5$ and the bond weakens.
Thus, the options $A$ and $D$ are correct.
Both $O_2$ and $O_2^{-}$ are paramagnetic due to presence of unpaired electrons.
They have bond orders $2$ and $1.5$ respectively.
Thus in the formation of oxygen monoanion, the bond $O-O$ order decreases.
Thus, the option $C$ is correct and the option $B$ is incorrect.