PCl5, PCl3 and Cl2 are at equilibrium at 500K in a closed container and their concentrations are 0.8 × 10–3 mol L–1, 1.2 × 10–3 mol L–1 and 1.2 × 10–3 mol L–1 respectively. The value of Kc for the reaction PCl5 (g) ⇄ PCl3 (g) + Cl2 (g) will be
(i) 1.8 × 103 mol L–1 (ii) 1.8 × 10–3 (iii) 1.8 × 10–3 L mol–1 (iv) 0.55 × 104