The reaction, NO2Cl(g)+Cl(g)NO2(g)+Cl2(g), was found to be first order in each of the two reactants and second order overall. The rate law is therefore rate=k[CCl]rate=k[NO2]2rate=k[NO2Cl][Clrate=k[NO2Cl][Cl][NO2][Cl2]rate=k[NO2][Cl2]