For the reversible reaction 2 SO₃(g) ⇌ 2 SO₂(g) + O₂(g)
CHEMISTRY · Single correct · A Level · Chemistry · Chemical equilibria (Le Chatelier’s principle and Kc) · Chemical equilibria (Le Chatelier’s principle and Kc)
Problem
For the reversible reaction 2 SO₃(g) ⇌ 2 SO₂(g) + O₂(g), the value of the equilibrium constant Kc increases when the reaction mixture is heated. Which statement about ΔH for the reaction is most accurate?
(a) ΔH cannot be determined from the information provided.
(b) ΔH is negative because heat behaves as a product in the balanced equation.
(c) ΔH is positive because heat behaves as a reactant in the balanced equation.
(d) ΔH is negative because increasing temperature always shifts an equilibrium toward the products, raising Kc.