For the equilibrium A 2 (g) ⇌ 2A(g) at 500 K, 4 moles of A 2 and 4 moles of A are taken and the total pressure is 10 bar. Given: Δ f G ° [A 2 (g)] = 17.2 kJ/mol and Δ f G ° [A(g)] = 10.0 kJ/mol. (R =

Question

For the equilibrium A 2 (g) ⇌ 2A(g) at 500 K, 4 moles of A 2 and 4 moles of A are taken and the total pressure is 10 bar. Given: Δ f G ° [A 2 (g)] = 17.2 kJ/mol and Δ f G ° [A(g)] = 10.0 kJ/mol. (R = 8.0 J/K/mol, ln 2 = 0.7, ln 10 = 2.3)

TestHub · Accepted Answer

Δ G ° = 2(10.0) - 17.2 = +2.8 kJ ln K P = -Δ G ° /RT = -2800/(8.0 × 500) = -0.7, so K P = 1/2 = 0.5 bar, so (b) is correct and (a) is wrong The mixture has 4 mol A 2 and 4 mol A, so P A2 = P A = 5 bar Q P = (5) 2 /5 = 5 bar Q P > K P , so the reaction goes backward, and (c) is correct Δ G = RTln(Q P /K P ) = (8.0)(500)ln 10 = 4000 × 2.3 = +9.2 kJ, which is positive, so (d) is wrong The correct statements are (b) and (c).

Chemistry - Chemical Equilibrium Question with Solution | TestHub

Options:(select one or more)

Doubts & Discussion