N2O4 at an initial pressure of 2atm. and 300k dissociates to an extent of 20% at the same temperature by the time equilibrium is established. Kp for the reaction 2NO2 ⇌N2O4 is

find Kp for N2O4 ⇌2NO2 then reverse Calculation of Kp for N2O4 ⇌2NO220% of N2O4 is decomposed = 20×2100=0.4pressure of each component present at equilibrium :N2O4 = 2-0.4=1.6 atmNO2 = 2×0.4 = 0.8 atmKp=PNO22PN2O4=0.8×0.81.6=0.4 atmFor 2NO2⇌N2O4Kp'=1Kp=10.4=2.5 atm-1