How does volume effect Le Chatelier's principle?
This principle dictates that systems at equilibriums will counteract external stress as to re-equilibrate.
Hence, when the volume of a container, wherein gases are reacting,
decreases: the system will decrease the moles of gas present, and shift to the right in the former case.
increases: the system will increase the moles of gas present, and shift to the left in the former case.