Rate law for the reaction $2 \mathrm{NO}+\mathrm{Cl}_2 \rightarrow 2 \mathrm{NOCl}$ is rate…
Rate law for the reaction $2 \mathrm{NO}+\mathrm{Cl}_2 \rightarrow 2 \mathrm{NOCl}$ is rate $=\mathrm{k}[\mathrm{NO}]^2\left[\mathrm{Cl}_2\right]$. When will the value of k increase?
by increasing temperature
. by increasing [NO]
by increasing $\left[\mathrm{Cl}_2\right]$
by increasing both [ NO$]$ and $\left[\mathrm{Cl}_2\right]$
Solution
Arrhenius equation $\mathrm{k}=\mathrm{Ae}^{-\mathrm{E}_{\mathrm{a}} / \mathrm{RT}}$ shows that, as the temperature rises, $\frac{\mathrm{E}_{\mathrm{a}}}{\mathrm{RT}}$ decreases. This causes an increase in $\mathrm{e}^{-\mathrm{E}_{\mathrm{a}} / \mathrm{RT}}$ which increases k and the rate of reaction.