Consider the endothermic reaction: $N_2O_4(g) \rightleftharpoons 2NO_2(g)$. A sealed container filled with an equilibrium mixture of $N_2O_4$ and $NO_2$ is suddenly immersed in an ice bath. Which of the following changes will occur initially?

On addition of an inert gas at constant volume to the reaction, ${{\rm{N}}_2} + 3{{\rm{H}}_2}\,\leftrightharpoons\,\,2{\rm{N}}{{\rm{H}}_3}$ at equilibrium:

On addition of an inert gas at constant volume to the reaction, ${{\rm{N}}_2} + 3{{\rm{H}}_2}\,\leftrightharpoons\,\,2{\rm{N}}{{\rm{H}}_3}$ at equilibrium: