Why does addition of inert gas at constant volume not affect equilibrium of system but addition of inert gas at constant pressure does affect it?
Dissociation obviously increases the number of moles.
The addition of an inert gas can affect the equilbrium, but only if the volume is allowed to change.
There are two cases on which equilibrium depends. These are:
Hence, when an inert gas is added to the system in equilibrium at constant volume there will be no effect on the equilibrium.
Consider the following reaction in equilibrium:
2NH3(g)↽⇀N2(g)+3H2(g)