Chapter 14, Problem 63GQ

At temperatures below 500 K, the reaction between carbon monoxide and nitrogen dioxide

CO(g) + NO₂(g) → CO₂(g) + NO(g)

has the following rate equation: Rate k[NO₂]². Which of the three mechanisms suggested here best agrees with the experimentally observed rate equation?

$\begin{array}{ll}\text{Mechanism 1}\hfill & \text{Single, elementary step}\hfill \\ \hfill & {\text{NO}}_{\text{2}}+\text{CO}\to {\text{CO}}_{\text{2}}+\text{NO}\hfill \\ \text{Mechanism 2}\hfill & \text{Two steps}\hfill \\ \text{Slow}\hfill & {\text{NO}}_{\text{2}}+{\text{NO}}_{\text{2}}\to {\text{NO}}_{\text{3}}+\text{NO}\hfill \\ \text{Fast}\hfill & {\text{NO}}_{\text{3}}+\text{CO}\to {\text{NO}}_{\text{2}}+{\text{CO}}_{\text{2}}\hfill \\ \text{Mechanism 3}\hfill & \text{Two steps}\hfill \\ \text{Slow}\hfill & {\text{NO}}_{\text{2}}\to \text{NO}+\text{O}\hfill \\ \text{Fast}\hfill & \text{CO}+\text{O}\to {\text{CO}}_{\text{2}}\hfill \end{array}$