For a reaction $\mathrm{A} ightarrow$ product, rate constant is $2 imes 10^{-2} \mathrm{~s}^{-1}$. The initial concentration of $\mathrm{A}$ is $1.0 \mathrm{~mol} \mathrm{dm}^{-3}$. What is the value of $\log \frac{1}{[\mathrm{~A}]_{\mathrm{t}}}$ after 100 seconds?

Question

For a reaction $\mathrm{A} ightarrow$ product, rate constant is $2 	imes 10^{-2} \mathrm{~s}^{-1}$. The initial concentration of $\mathrm{A}$ is $1.0 \mathrm{~mol} \mathrm{dm}^{-3}$. What is the value of $\log \frac{1}{[\mathrm{~A}]_{\mathrm{t}}}$ after 100 seconds?

Aicharya · Accepted Answer

$\begin{aligned} & \mathrm{k}=2 	imes 10^{-2} \mathrm{~s}^{-1} 	ext { (first order reaction) } \ & 2.303 \log \frac{[\mathrm{A}]_0}{[\mathrm{~A}]_{\mathrm{t}}}=\mathrm{kt} \ & \left([\mathrm{A}]_0=1 \mathrm{M}ight) \log \frac{1}{[\mathrm{~A}]_{\mathrm{t}}}=\frac{\mathrm{k}}{2.303} 	imes \mathrm{t}=\frac{2 	imes 10^{-2} 	imes 100}{2.303}=0.868\end{aligned}$

For a reaction $\mathrm{A} \rightarrow$ product, rate constant is $2 \times 10^{-2} \mathrm{~s}^{-1}$. The…

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