At some temperature, the equilibrium of the homogeneous system 2NO (gas) + O2 (gas) = ​​2NO2 (gas) was established at the following concentrations of reactants: [NO] = 0.20 mol/l; [O2] = 0.10 mol/l; [NO2] = 0.10 mol/l. Calculate the equilibrium constant of this reaction and the initial concentrations of NO and O2