2 NO ( g ) + Cl 2 (   g ) ⇌ 2 NOCl ( s ) This reaction was studied at - 10 ° C and the…

$2\mathrm{NO}\left(\mathrm{g}\right)+{\mathrm{Cl}}_2( \mathrm{g})\rightleftharpoons 2\mathrm{NOCl}\left(\mathrm{s}\right)$
This reaction was studied at $-10°\mathrm{C}$ and the following data was obtained

$\begin{array}{cccc}\mathrm{run}& [\mathrm{NO}{]}_0& {\left[{\mathrm{Cl}}_2\right]}_0& \hspace{0.25em}\hspace{0.25em}\hspace{0.25em}{\mathrm{r}}_0\\ 1& 0.10& 0.10& 0.18\\ 2& 0.10& 0.20& 0.35\\ 3& 0.20& 0.20& 1.40\end{array}$

$[\mathrm{NO}{]}_0$ and ${\left[{\mathrm{Cl}}_2\right]}_0$ are the initial concentrations and ${\mathrm{r}}_0$ is the initial reaction rate. The overall order of the reaction is
(Round off to the Nearest Integer).