The half-life period for the reaction, ${\mathrm{N}}_2{\mathrm{O}}_5\to 2{\mathrm{NO}}_2+\frac{1}{2}{\mathrm{O}}_2$ is $2.4$ hours at $30°\mathrm{C}$. What time would be required to reduce $5\times {10}^{10}$ molecules of ${\mathrm{N}}_2{\mathrm{O}}_5$ to ${10}^8$ molecules?

One mole of a gas $\mathrm{A}$ and two moles of a gas $\mathrm{B}$ are introduced into one vessel and $2$ moles of $\mathrm{A}$ and $1$ mole of $\mathrm{B}$ into a second vessel having the same capacity. The temperature is the same in both vessels. Will the rate of reaction between $\mathrm{A}$ and $\mathrm{B}$ in these vessels differ if it is expressed by the equation

(i) rate $=\mathrm{k} \left[\mathrm{A}\right] \left[\mathrm{B}\right]$ and (ii) rate $=\mathrm{k} [\mathrm{A}{]}^2 [\mathrm{B}]?$

For the reaction $\mathrm{A}\to \mathrm{B}+\mathrm{C}$ the following data were obtained: 

$\begin{array}{lccr}t\left(\mathrm{s}\right)& 0& 900& 1800\\ \left[\mathrm{A}\right]& 50.8& 19.7& 7.62\end{array}$

What is the order of the reaction?

Nitrosyl chloride, $\mathrm{NOCl}$ decomposes to $\mathrm{NO}$and ${\mathrm{Cl}}_2.$ $2\mathrm{NOCl}\left(\mathrm{g}\right)\to 2\mathrm{NO}\left(\mathrm{g}\right)+{\mathrm{Cl}}_2\left(\mathrm{g}\right)$ From the following data, determine the rate constant for this reaction. 

$\begin{array}{|cccc|}\hline \left[\mathrm{NOCl}\right]:& 0.10& 0.20& 0.30\\ \text{ Rate (mol/L/s) }& 8\times {10}^{-10}& 3.2\times {10}^{-9}& 7.2\times {10}^{-9}\\ \hline\end{array}$

If the value is of type $\mathrm{y}\times {10}^{-7} \mathrm{L}/\mathrm{mol}-\sec$, report the value of $\mathrm{y}$.