At 473 K, the equilibrium constant K_c for the decomposition of phosphorus pentachloride(PCl_5) is 8.3 10^(-3) .If decomposition proceeds as : PCl_5(g) hArr PCl_(3) + PCl_(3)(g) + Cl_(2)(g), Delta H =+ 124.0 Kj mol ^(-1) (a) Write an expression for K_C for the reaction. (b) What is the value of K for the reverse reaction at the same temperature. (c) What would be the effect on K_C if(i) More of PCl_3 is added (ii) Temperature is increased

At 473 K, the equilibrium constant K_c for the decomposition of phosph

1.	At 473 K, the equilibrium constant K_c for the decomposition of phosphorus pentachloride(PCl_5) is 8.3 10^(-3) .If decomposition proceeds as : PCl_5(g) hArr PCl_(3) + PCl_(3)(g) + Cl_(2)(g), Delta H =+ 124.0 Kj mol ^(-1) (a) Write an expression for K_C for the reaction. (b) What is the value of K for the reverse reaction at the same temperature. (c) What would be the effect on K_C if(i) More of PCl_3 is added (ii) Temperature is increased
Answer» Solution :The expression for `K_(C)=(PCl_3(g)[Cl_2(g)])/([PCl_5(g)])` b. For reverse reaction `(K._c) = (PCl_5(g))/([PCl_5(g)][Cl_2(g)]) = (1)/(8.3 xx 10^(-3)) =0 120.48 ` (i) By adding more of PCI,, VALUE of Ko will remain constant because there is no change in TEMPERATURE. (ii) By increasing the temperature the orward reaction will be FAVOURED since it is endothermic in nature. Therefore, the value of equilibrium constant will INCREASE