AB2 dissociates as :  When the intial pressure of AB2 is 500 mm Hg, the total equilibrium pressure is 700 mm Hg. Calculate equilibrium constant for the reaction, assuming that the volume of the system remains unchanged.

Initial pressure of AB2 (g) = 500 mmEquilibrium pressure = 700 mmLet 'P' mm of AB2 decomposed at equilibrium2 mole of AB2 gives 1 mole of ABPmm of AB2 gives _____ mm of ABPressure of AB at equilibrium = 'P' mm1 moles of AB2 gives 1 mole of BPmm of AB2 gives ____ mm of BPressure of AB at equilibrium = 'P' mmTotal pressure at equilibrium = 500 - P + P + P = 500 + PGiven (500 + P) = 700At equilibriumKp = 133.33 mm