Introduction to Le Chatelier's Principle Practice Test

A student has a reaction mixture at equilibrium in a closed flask: $\text{H}_2(g) + \text{I}_2(g) \rightleftharpoons 2\text{HI}(g)$. The student then removes some $\text{HI}(g)$ from the flask. As the system responds to this stress to re-establish equilibrium, in which direction does the equilibrium shift?

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?