Question

Consider two containers A and B where A is a rigid container and B is a container with a massless, frictionless piston that maintains constant pressure. NH₃ (g) is injected into both containers and allowed to come to equilibrium. At equilibrium, 2 atm of Argon gas is injected into each container. Explain any changes (up, down or no change) to the equilibrium concentrations of NH₃ , N₂ and H₂ ?

Answer 1

This queston is based upon the application of Lee chatelier's Principal. On adition of inert gas

N2+3H2 <==> 2NH3

So no. of moles is greater on the side of reactant.

Since the firs container has fixed volume so on addition of inert gas i.e. Argon pressure will increase and equilibrium will shift in forward direction. It will lead to more production of ammonia NH3 and simultaneously N2 and H2 will decrease. In the second container volume is variable so no extensive pressure development will take place. At equilibrium there will not be any change in the concentrations of N,H2 and NH3.