Question

Here, ${N_2}$ and ${O_2}$ are converted into monoanions, $N_2^ - $ and $O_2^ - $ respectively. Which of the following statement(s) is /are correct.
(a) In $N_2^ - $, the $N - N$ bond weakens than ${N_2}$.
(b) In $O_2^ - $, the $O - O$ bond order increases than in ${O_2}$.
(c) In $O_2^ - $, the $O - O$ bond order decreases than in ${O_2}$.
(d) $N_2^ - $ becomes paramagnetic.

Answer 1

Hint: We know that Bond order is the quantity of substance connections between couples of molecules and demonstrates the steadiness of a security. For instance, in diatomic nitrogen, \[N \equiv N\], the bond order is three; in acetylene, \[H - C \equiv C - H\] , the carbon-carbon bond order is additionally three, and the \[C - H\] bond order is one. Bond order and bond length demonstrate the sort and strength of covalent connections between particles. Bond order and length are contrarily relative to one another: when bond order is expanded, bond length is diminished.

Complete answer:
We need to know that the oxygen has two unpaired electrons in its \[\pi * \] orbitals; one electron goes to \[\pi * \] orbital to frame \[{O_2}^ - \].
The Bond order in oxygen atom (\[{O_2}^ - \]) can be calculated as,
$B.N = 0.5\left[ {\left( {{\text{Number of holding electrons}}} \right) - \left( {{\text{Number of hostile to holding electrons}}} \right)} \right]$
Now we can substitute the known values we get,
$B.N = 0.5\left[ {10 - 7} \right]$
On simplification we get,
$B.N = 1.5$
Along these lines, bond order of \[{O_2}^ - \] decreases.
Similarly one electron goes to \[\pi * \] orbital to shape \[{N_2}^ - \] and bond order diminishes and it additionally becomes para attractive. Along these lines, the right answer is B.

Note:
Now we can discuss about the diamagnetism and paramagnetism as,
Diamagnetism: Diamagnetic substances tend to move from the more grounded part to the more vulnerable piece of the outside attractive field. We can likewise say that the diamagnetic substances get repulsed by a magnet.
Paramagnetism: Paramagnetic substances are those substances that get pitifully polarized within the sight of an outside attractive field. Within the sight of an outside attractive field, these substances will in general move from a district of a powerless to a solid attractive field. In different terms, we can say that these substances will in general get pitifully pulled in to a perpetual magnet. In a paramagnetic material, the individual particles have a dipole second, which when put in an attractive field, collaborate with each other, and get unexpectedly adjusted in a typical way, which brings about its polarization. According to Curie's law, the attraction of a paramagnetic substance is contrarily relative to the supreme temperature, until it arrives at a condition of immersion.