For the given reaction, 2A(g)+B2(g)⇌2AB2(g) The equilibrium constant, Kp=PA2⋅PB2PAB22=16...(i) For the other given reaction, AB2(g)⇌A(g)+21B2(g) The equilibrium constant, Kp′=PAB2PA⋅PB21/2...(ii) On squaring Eq.(ii), we obtain, (Kp′)2=PAB22PA2⋅PB2...(iii) Now, from Eq.(i) and (ii), we obtain, Kp⋅(Kp′)2=1⇒16⋅(Kp′)2=1(∵Kp=16.0)⇒(Kp′)=[161]1/2⇒Kp′=41=0.25