Chemical Kinetics

A complex reaction takes place in following steps.

$$ \begin{aligned} & \mathrm{NO}_2 \mathrm{Cl}_{(\mathrm{g})} \longrightarrow \mathrm{NO}_{2(\mathrm{~g})}+\mathrm{Cl}_{(\mathrm{g})} \text { (slow) } \\ & \mathrm{NO}_2 \mathrm{Cl}_{(\mathrm{g})}+\mathrm{Cl}_{(\mathrm{g})} \longrightarrow \mathrm{NO}_{2(\mathrm{~g})}+\mathrm{Cl}_{2(\mathrm{~g})} \text { (fast) } \end{aligned} $$

Identify rate law equation for this reaction.