Question

The most stable oxide of nitrogen will be:
(A) $2N{O_{\left( g \right)}} \rightleftharpoons {N_{2\left( g \right)}} + {O_{2\left( g \right)}};K = 2.2 \times {10^{30}}$
(B) $2{N_2}{O_{\left( g \right)}} \rightleftharpoons 2{N_{2\left( g \right)}} + {O_{2\left( g \right)}};K = 3.5 \times {10^{30}}$
(C) $2{N_2}{O_5}_{\left( g \right)} \rightleftharpoons 2{N_{2\left( g \right)}} + {O_{2\left( g \right)}};K = 1.2 \times {10^{24}}$
(D) $N{O_2}_{\left( g \right)} \rightleftharpoons 2N{O_{\left( g \right)}} + {O_{2\left( g \right)}};K = 6.7 \times {10^{16}}$

Answer 1

The equilibrium constant of a chemical reaction can be defined as the ratio of concentration of reactants and concentration of products. The equilibrium constant of oxides is inversely proportional to stability of oxides. The oxide with low value of equilibrium constant is the stable oxide.

Complete answer:
Nitrogen is an element with atomic number $7$ and forms oxides with oxygen and is called nitrogen oxides. Nitrogen oxides are of different types, like nitrous oxide and nitric oxide.
Some of the nitrogen oxides are stable and some other oxides are unstable.
Different nitrogen oxides include nitrogen oxide or nitrogen monoxide.
Nitrous oxide is an oxide with molecular formula ${N_2}O$ .
Dinitrogen pentoxide is an oxide with molecular formula ${N_2}{O_5}$ .
Nitrogen dioxide is an oxide with molecular formula $N{O_2}$ .
For all the above oxides the equilibrium constant is given.
The oxide with low equilibrium constant cannot undergo complete dissociation and hence that oxide will be more stable.
In the given oxides nitrogen dioxide has a lower value of equilibrium constant and thus, this nitrogen oxide is more stable than the other oxides.
Nitrogen dioxide is the most stable oxide.
Thus, option D is the correct one.

Note:
The relation between the equilibrium constant and stability of oxides are inversely proportional. Thus, these are opposite to each other. The nitrous oxide has high equilibrium constant and leads to its lower stability. Thus, nitrous oxide is the least stable oxide and nitrogen oxide is the stable oxide.