Question

Among the oxides of nitrogen ${{\text{N}}_{2}}{{\text{O}}_{3}}\text{, }{{\text{N}}_{2}}{{\text{O}}_{4}}\text{ and }{{\text{N}}_{2}}{{\text{O}}_{5}}$;molecule(s) having nitrogen-nitrogen bond is/are:
$\begin{align}
& \text{A}\text{. Only }{{\text{N}}_{2}}{{\text{O}}_{5}} \\
& \text{B}\text{. }{{\text{N}}_{2}}{{\text{O}}_{3}}\text{ and }{{\text{N}}_{2}}{{\text{O}}_{4}} \\
& \text{C}\text{. }{{\text{N}}_{2}}{{\text{O}}_{3}}\text{ }\text{and }{{\text{N}}_{2}}{{\text{O}}_{5}} \\
& \text{D}\text{. }{{\text{N}}_{2}}{{\text{O}}_{4}}\text{ and }{{\text{N}}_{2}}{{\text{O}}_{5}} \\
\end{align}$

Answer 1

Hint: Electronic configuration of the nitrogen is \[\text{1}{{\text{s}}^{2}}\text{ 2}{{\text{s}}^{2}}\text{ 2}{{\text{p}}^{3}}\] due to which it can form 3 bonds easily with other atoms. The electronegativity of oxygen is more than the nitrogen because of its larger size than nitrogen. Electronegativity is the tendency of an element to attract a pair of electrons from another element.

Complete Solution:
 -We have to identify the N - N bond from the given three compounds of nitrogen oxide which are also known as acidic oxides.
-So, firstly we have to draw the structure of nitrogen trioxide, nitrogen tetroxide and nitrogen penta-oxide which have molecular formula of ${{\text{N}}_{2}}{{\text{O}}_{3}}\text{, }{{\text{N}}_{2}}{{\text{O}}_{4}}\text{ and }{{\text{N}}_{2}}{{\text{O}}_{5}}$ respectively.

-So, we can see that only ${{\text{N}}_{2}}{{\text{O}}_{3}}$ and ${{\text{N}}_{2}}{{\text{O}}_{4}}$ have only one N-N bond.
-In ${{\text{N}}_{2}}{{\text{O}}_{5}}$, there is 3 N - O and 2 N = O bond and not N-N bond so it will be the incorrect answer.
-The name of the compound ${{\text{N}}_{2}}{{\text{O}}_{3}}$ is nitrogen trioxide and it is formed when the nitrogen oxide and nitrogen dioxide reacts together i.e. \[\text{NO + N}{{\text{O}}_{2}}\to \text{ }{{\text{N}}_{2}}{{\text{O}}_{3}}\].
-Whereas when two molecules of nitrogen oxide dimerise with each other they form nitrogen tetroxide i.e. \[2\text{N}{{\text{O}}_{2}}\ \rightleftharpoons \text{ }{{\text{N}}_{2}}{{\text{O}}_{4}}\]
-Moreover, the oxidation state of nitrogen in nitrogen trioxide, nitrogen tetroxide and nitrogen penta-oxide is +2, +3 and +5.
-So, only nitrogen trioxide and nitrogen tetroxide will have a N - N bond.

Note: Nitrogen can form maximum of 3 covalent bond and 1 co-ordinate bond because according to the electronic configuration it has ability to form 3 bonds easily but in some cases, it can also share some a pair electron i.e. lone pair which forms coordination bond.