Question

Given the following proposed mechanism, predict the rate law for the overall reaction.2NO2 + Cl2 → 2NO2Cl (overall reaction)MechanismNO2 + Cl2 → NO2Cl + Cl slowNO2 + Cl → NO2Cl fastRate = k[NO2][Cl2]Rate = k[NO2]2[Cl2]2Rate = k[NO2Cl][Cl]2Rate = k[NO2][Cl]Rate = k[NO2Cl]2

Answer 1

Answer: The rate law for the reaction is $\text{Rate}=k[NO_2][Cl_2]$

Explanation:

In a mechanism of the reaction, the slow step in the mechanism always determines the rate of the reaction.

For the given chemical reaction:

$2NO_2+Cl_2\rightarrow 2NO_2Cl$

The intermediate reaction of the mechanism follows:

Step 1:  $NO_2+Cl_2\rightarrow NO_2Cl+Cl;\text{ (slow)}$

Step 2:  $NO_2+Cl\rightarrow NO_2Cl;\text{(fast)}$

As, step 1 is the slow step. It is the rate determining step

Rate law for the reaction follows:

$\text{Rate}=k[NO_2][Cl_2]$

Hence, the rate law for the reaction is $\text{Rate}=k[NO_2][Cl_2]$