At a given temperature the Kc for the reaction,
PCl5 (g) ⇌ PCl3 (g) + Cl2 (g) is 2.4 x10-3. At the same temperature, the Kc for the reaction
PCl3 (g) + Cl2 (g) ⇌ PCl5 (g) is :
(a) 2.4x10-3 (b) -2.4 x10-3
(c) 4.2 x102 (d) 4.8 x10-2