For 2SO2+O2⇌2SO3 , equilibrium pressures of SO3  & O2  are 0.4 atm & 0.2 atm respectively. If the total pressure is 1 atm, Kp for 2SO3⇌2SO2+O2 is

Given, PSO3=0.4 atm           Peq=PSO2+PSO3+PO2                 PO2   =   0.2 atm            ⇒PSo2=1−0.6=0.4 atm                   PSO2=  ?                          2SO3⇌2SO2+O2        Kp=(0.4)2(0.2)(0.4)2               =0.4×0.4×0.20.4×0.4                 =0.2 atm