This question is related to Le Chatelier's Principle, which states that if a system at equilibrium is subjected to a change in concentration, pressure, or temperature, the system will shift in such a direction as to counteract the change and restore equilibrium. Let's analyze each option:
- Option (1): Addition of – This will shift the equilibrium towards the right (formation of more ) to counteract the increase in .
- Option (2): Removal of – This will also shift the equilibrium towards the right to produce more .
- Option (3): Addition of – Similar to option (1), this will shift the equilibrium towards the right to counteract the increase in .
- Option (4): Addition of – Helium is an inert gas that does not react with the other gases in the equilibrium. Adding an inert gas does not affect the equilibrium position because it does not change the partial pressures of the reactants or products. Thus, the correct answer is .