Question

The following reaction is exothermic. For a system at equilibrium, which change will shift the equilibrium to the left? 2 SO₂(g) + O₂(g) ⇌ 2 SO₃(g)

1) Decreasing the concentration of SO₂
2) Increasing the concentration of O₂
3) Increasing the concentration of SO₃
4) Increasing the temperature

Answer 1

For the exothermic reaction 2 SO₂(g) + O₂(g) ⇌ 2 SO₃(g), increasing the temperature will shift the equilibrium to the left according to Le Chatelier's Principle.

Step-by-step explanation:

The question pertains to chemical equilibrium and Le Chatelier's Principle, which predicts how a change in conditions can affect the position of equilibrium. For the exothermic reaction 2SO2(g) + O2(g) ⇌ 2SO3(g), decreasing the temperature would also shift the equilibrium to the left, because heat is produced in the reaction and lowering temperature effectively decreases the 'concentration' of the heat product. Out of the options provided, increasing the temperature is the change that will shift the equilibrium to the left because, for exothermic processes, heat can be considered a product, and increasing temperature adds heat to the system, which the system counteracts by shifting to the left to absorb the extra heat.