The exothermic formation of ${\text{ClF}}_3$ is represented by the equation:
$${\text{Cl}}_2(g)+3{\text{F}}_2(g)\rightleftharpoons 2{\text{ClF}}_3(g);{\Delta }_{r}H=-329\text{kJ}$$
Which of the following will increase the quantity of ${\text{ClF}}_3$ in an equilibrium mixture?

According to Le Chatelier's Principle:Temperature: Since the reaction is exothermic, increasing temperature shifts equilibrium to the left.Reactants: Adding a reactant (${\text{Cl}}_2$ or ${\text{F}}_2$) shifts the equilibrium to the right, increasing product formation. Adding ${\text{F}}_2$ works.Removing ${\text{Cl}}_2$: Shifts equilibrium to the left.Volume/Pressure: Increasing volume decreases pressure. The equilibrium shifts toward the side with more moles of gas (left, $4$ moles vs $2$ moles).