Effect of an Inert Gas
The influence of adding a non-reacting gas on the position of a gaseous equilibrium.
Unit
Pa
In depth
Added at constant volume, an inert gas raises total pressure but leaves every partial pressure unchanged, so the equilibrium does not shift. Added at constant total pressure, it forces the volume to expand, diluting the reacting gases and shifting the equilibrium towards more gas molecules.
Examples in the real world
Adding argon to a sealed PCl₅ vessel does nothing; adding it at constant pressure increases dissociation.