Calculate the rate constant for the first order reaction, $\mathrm{A} \rightarrow \mathrm{B}$ if the rate of…
Calculate the rate constant for the first order reaction, $\mathrm{A} \rightarrow \mathrm{B}$ if the rate of reaction is $5.4 \times 10^{-6} \mathrm{~mol} \mathrm{dm}^{-3} \mathrm{~s}^{-1}$ and $[\mathrm{A}]=0.3 \mathrm{M}$.
$1.8 \times 10^{-5} \mathrm{~s}^{-1}$
$1.5 \times 10^{-5} \mathrm{~s}^{-1}$
$2.1 \times 10^{-5} \mathrm{~s}^{-1}$
$2.4 \times 10^{-5} \mathrm{~s}^{-1}$
Solution
For the first order reaction, $\mathrm{A} \longrightarrow \mathrm{B}$, Rate $=\mathrm{k}[\mathrm{A}]$
$\begin{aligned}
\therefore \quad \mathrm{k} & =\frac{\text { Rate }}{[\mathrm{A}]}=\frac{5.4 \times 10^{-6} \mathrm{~mol} \mathrm{dm}^{-3} \mathrm{~s}^{-1}}{0.3 \mathrm{~mol} \mathrm{dm}^{-3}} \\
& =1.8 \times 10^{-5} \mathrm{~s}^{-1}
\end{aligned}$