How does an inert gas affect the equilibrium of a reversible reaction?

Question

This reaction can be used:

PCl5 <==> PCl3 + Cl2

I want the effect when it is added at constant volume. The reason should be explained.

Answer 1

the effect of the increase in moles can be artificially decreased by adding an inert material, as this reaction is in the gaseous pha se then increasing the no of total moles as a result of adding an inert gas will increase the ratio of products to the reactants and decrease mass per unit volume

Answer 2

at constant volume addition of inert gas has no effect.
If volume is held constant, the concentrations of the above gases do not change. The partial pressures of the gases in the reaction do not change, even though we have increased the total pressure by adding the inert gas. Therefore, there is no change in equilibrium

Answer 3

when an inert gas is added at constant volume though the volume remains constant the no. of moles increase and hence the pressure is increased and according to the le chaterliers principle the reversible reaction(rate of forward of backward reaction) is affected

Answer 4

i been trying to figure that out myself