NCERT Class XI Chemistry Equilibrium Solutions

(a) Kc =

[PCl3(g)][Cl2(g)]

[PCl5(g)]

(b) PCl3(g)+Cl2(g) ⇌ PCl5(g)
∴ Kc′ =

[PCl5(g)]

[PCl3(g)][Cl2(g)]

(c) PCl5(g) ⇌ PCl3(g)+Cl2(g)
(i) If more PCl5 is added, then Qc becomes less than Kc, the reaction will shift in the forward direction.
(ii) If the pressure is increased, the reaction will shift towards backward direction as it contains less number of gaseous species.
(iii) As the reaction is endothermic, the increase in temperature will favour the forward reaction. More PCl5 will dissociate to form PCl3 and Cl2.