The following reaction descomposes ${\text{N}}_{\text{2}}{\text{O}}_{\text{5}}\to {\text{2NO}}_{\text{2}}+\frac{1}{2}{\text{O}}_{\text{2}}.$ At a $25$ degree centigrade the rate constant of the reaction is $5\times 10^{-2}{\sec }^{-1}$. The initial pressure of ${\mathrm{N}}_2{\mathrm{O}}_5$ is $\text{0}\text{.2}\text{atm}\text{.}$ If total pressure of gaseous mixture becomes $\text{0}\text{.35}\text{atm,}$ then calculate the time of decomposition of ${\mathrm{N}}_2{\mathrm{O}}_5$.