Introduction to Le Chatelier's Principle Practice Test

A closed container holds the gaseous equilibrium system $2\text{SO}_2(g) + \text{O}_2(g) \rightleftharpoons 2\text{SO}_3(g)$. After equilibrium is established, the volume of the container is decreased by moving a piston inward. As the system responds to this stress to re-establish equilibrium, in which direction does the equilibrium shift?

A sealed flask contains the equilibrium mixture for $\mathrm{H_2(g) + I_2(g) \rightleftharpoons 2HI(g)}$. After equilibrium is established, some $\mathrm{I_2(g)}$ is removed from the flask. In response to this stress, which direction will the system shift to re-establish equilibrium?