Assuming steady-state approximation for [Cl] and [COCl], the rate law for the formation of COCl2 is — Chemical Kinetics Chemistry Question

💡 Solution & Explanation

Applying steady state to [COCl]: K3[Cl][CO] = K4[COCl] + K5[COCl][Cl2], so [COCl] = K3[Cl][CO]/(K4+K5[Cl2]). Applying steady state to [Cl] and combining gives 2K1[Cl2] = 2K2[Cl]^2, so [Cl] = (K1/K2)^1/2 [Cl2]^1/2. Rate = K5[COCl][Cl2] = K5 K3 [Cl][CO][Cl2]/(K4+K5[Cl2]). Substituting [Cl] yields the expression in option (c). Therefore, correct answer is C.