The reaction between phosphorous trichloride (PCl3) and chlorine (Cl2) produces phosphorous pentachloride (PCl5).
PCl3(g) + Cl2(g) ⇌ PCl5(g)
A 1.00 L reaction vessel is charged with 0.25 mol PCl3, 0.45 mol Cl2 and 0.18 mol of PCl5. When the equilibrium state is achieved, the reaction mixture contains 0.080 mol PCl3 and 0.35 mol PCl5, Calculate the equilibrium constant, Kc, for this reaction.