Let the concentration of N_{2}O at equilibrium be x.

The given reaction is:

Therefore, at equilibrium, in the 10 L vessel:

The value of equilibrium constant i.e. K_{c} = 2.0 × 10^{–37} is very small. Therefore, the amount of N_{2} and O_{2} reacted is also very small. Thus, x can be neglected from the expressions of molar concentrations of N_{2} and O_{2}. Then,