If you have a chemical reaction involving gases and the same number of moles of gas on both sides of the reaction, and you increase the pressure, the equilibrium position of the reaction may shift in a particular direction based on Le Chatelier's principle. Le Chatelier's principle states that if a system at equilibrium is subjected to a change, it will adjust itself in a way that counteracts that change.
When you increase the pressure, the system will attempt to reduce the pressure by shifting the equilibrium position in the direction that results in fewer moles of gas. This is because decreasing the number of gas molecules will decrease the overall pressure.
Let's consider a hypothetical reaction for illustration:
A (g) + B (g) ⇌ C (g) + D (g)
Assuming that A and B have the same number of moles as C and D (1:1 ratio on both sides), if you increase the pressure by decreasing the volume or adding an inert gas, the equilibrium position will shift towards the side with fewer moles of gas to counteract the pressure increase. In this case, that would mean shifting towards the side of the reaction with A and B.
So, in summary, if you have the same number of moles of gas on both sides of the reaction and you increase the pressure, the equilibrium position will shift in the direction that reduces the total number of gas molecules to alleviate the pressure increase.