For a reaction equilibrium, N2O4(g)⇌2NO2(g), the concentrations of N2O4 and NO2 at equilibrium are 4.8×10−2 and 1.2×10−2 mol/L respectively. The value of Kc, for the reaction is:
According law
of active mass,
Kc=[NO2]2[N2O4]=[1.2×10−2]24.8×10−2
=0.3×10−2=3×10−3