2SO3(g) ↔ 2SO2(g) + O2(g) 1.) What happens when sulfur dioxide is removed from the system.2.)Sulfur trioxide is added to the system.?

2SO₃(g) ⇌ 2SO₂(g) + O₂(g)

1.
When sulfur dioxide is removed from the system, according to Le Chatelier's principle, the equilibrium position will shift to the right to counteract the removal of sulfur dioxide, i.e. to increase the concentration of sulphur dioxide.  Therefore, the concentration of sulfur trioxide will decrease, and the concentrations of sulfur

dioxide and oxygen will increase.

2.
When sulfur trioxide is added to the system, according to Le Chatelier's principle, the equilibrium position will shift to the right to counteract the addition of sulfur trioxide, i.e. to decrease the concentration of sulfur trioxide.  Therefore, the concentration of sulfur trioxide will decrease, and the concentrations of sulfur dioxide and oxygen will increase.