Chapter 13, Problem 13.55QP

The rate law for the reaction

$2\text{NO}(g)+{\text{Cl}}_2(g)\stackrel{}{\to }2\text{NOCl}(g)$

is given by rate = k[NO][Cl₂]. (a) What is the order of the reaction? (b) A mechanism involving the following steps has been proposed for the reaction:

$\begin{array}{l}\text{NO}(g)+{\text{Cl}}_2(g)\stackrel{}{\to }{\text{NOCl}}_2(g)\\ {\text{NOCl}}_2(g)+\text{NO}(g)\stackrel{}{\to }2\text{NOCl}(g)\end{array}$

If this mechanism is correct, what does it imply about the relative rates of these two steps?