The correct option is B 5
Initially, number of moles of SO2,O2andSO3 are 2, 1.5 and 0 respectively.
2 moles of KMnO4 reacts with 5 moles of SO2.
0.4 moles of KMnO4 will react with 1 moles of SO2.
Thus at equilibrium number of moles of SO2,O2andSO3 are 1, 1 and 1 respectively.
The volume is 5 L.
Thus the equilibrium concentrations of SO2,O2andSO3 are 0.2, 0.2 and 0.2 respectively.
The expression for the equilibrium constant is Kp[SO3]2[SO2]2[O2]=0.220.22×0.2=5.