Give two examples for gaseous first order reactions

First order Reaction: The rate of reaction is directly proportional to one power of concentration of reactant in a chemical reaction.
1) Hydrogenation of ${\mathrm{C}}_2{\mathrm{H}}_4\text{ to }{\mathrm{C}}_2{\mathrm{H}}_6$
${\mathrm{C}}_2{\mathrm{H}}_{4\left(\mathrm{g}\right)}+{\mathrm{H}}_{2\left(\mathrm{g}\right)}\to {\mathrm{C}}_2{\mathrm{H}}_{6\left(\mathrm{g}\right)}$
where rate = $\mathrm{k}\left[{\mathrm{C}}_2{\mathrm{H}}_4\right]$
2) Decomposition of ${\mathrm{N}}_2{\mathrm{O}}_5$
${\mathrm{N}}_2{\mathrm{O}}_{5\left(\mathrm{g}\right)}\to 2{\mathrm{NO}}_{2\left(\mathrm{g}\right)}+\frac{1}{2}{\mathrm{O}}_{2\left(\mathrm{g}\right)}$
where rate = $\mathrm{k} \left[{\mathrm{N}}_2{\mathrm{O}}_5\right]$