At 450 °C the equilibrium constant for the reaction 2 SO₂(g) + O₂(g) ⇌ 2 SO₃(g) is…
CHEMISTRY · Multi-part · A Level · Chemistry · Chemical equilibria (Le Chatelier’s principle and Kc) · Chemical equilibria (Le Chatelier’s principle and Kc)
Problem
At 450 °C the equilibrium constant for the reaction
2 SO₂(g) + O₂(g) ⇌ 2 SO₃(g)
is K_c = 4.3 × 10². A reaction mixture at the same temperature has the following concentrations: [SO₂] = 0.10 M, [O₂] = 0.20 M, and [SO₃] = 0.60 M.
(a) Calculate the numerical value of the reaction quotient for the mixture.
(b) Compare the value obtained in part (a) with K_c and state whether the forward or reverse reaction is thermodynamically favored at this moment.
(c) Specify the sign of ΔG for the forward reaction under these conditions.
(d) Identify which species’ concentration will increase as the system moves toward equilibrium, and justify your answer.