What is the half life of a first order reaction if time required to decrease concentration of reactant from 0.8 M to 0.2 M is 12 hour?

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Aicharya · Accepted Answer

For the first order reaction, $\begin{array}{ll} & k=\frac{2.303}{t} \log _{10} \frac{[\mathrm{~A}]_0}{[\mathrm{~A}]_{\mathrm{t}}}=\frac{2.303}{12 	ext { hour }} \log _{10} \frac{[0.8]}{[0.2]} \ 	herefore & \mathrm{k}=0.1919 	imes 0.6020=0.1155 	ext { hour }^{-1} \ 	herefore & \mathrm{t}_{\mathrm{l} / 2}=\frac{0.693}{0.1155 \mathrm{~h}^{-1}}=6 	ext { hour } \end{array}$

What is the half life of a first order reaction if time required to decrease concentration of reactant from…

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