For a reaction, $2{\mathrm{NO}}_{\left(\mathrm{g}\right)}+{\mathrm{Cl}}_{2\left(\mathrm{g}\right)}\rightleftharpoons 2{\mathrm{NOCl}}_{\left(\mathrm{g}\right)}$
When concentration of ${\mathrm{Cl}}_2$ is doubled, the rate of reaction becomes two-times of the original. When the concentration of $\mathrm{NO}$ is doubled the rate becomes four times. What is the order of the reaction ?

For the reaction ${\mathrm{N}}_2+3{\mathrm{H}}_2⟶2{\mathrm{NH}}_3, \frac{-\mathrm{\Delta }\left[{\mathrm{NH}}_3\right]}{\mathrm{\Delta t}}=2\times {10}^{-4} \mathrm{mol} {\mathrm{lit}}^{–}{\sec }^{–1}.$ 

The value  of $\frac{-\mathrm{\Delta }\left[{\mathrm{H}}_2\right]}{\mathrm{\Delta t}}$ would be:

Consider a first-order gas-phase decomposition reaction given below:

$\mathrm{A}\left(\mathrm{g}\right)⟶\mathrm{B}\left(\mathrm{g}\right)+\mathrm{C}\left(\mathrm{g}\right)$

The initial pressure of the system before decomposition of $\mathrm{A}$ was ${\mathrm{p}}_{\mathrm{i}}.$ After the lapse of time $\text{'}\mathrm{t}\text{'},$ total pressure of the system increased by $\mathrm{x}$ units and became $\text{'}{\mathrm{p}}_{\mathrm{t}}\text{'}.$ The rate constant $\mathrm{k}$ for the reaction is given as-