In a first order reaction $60 \%$ of reactant decomposes in 4.606 $\min$. What is half life of reaction?…
In a first order reaction $60 \%$ of reactant decomposes in 4.606 $\min$. What is half life of reaction? $\left(\mathrm{k}=0.1989 \mathrm{~min}^{-1}\right)$
3.48 min
2.4 min
3.0 min
1.74 min
Solution
For 1st order reaction,
$\begin{aligned}
& \mathrm{t}_{1 / 2}=\frac{\ln 2}{\mathrm{k}}=\frac{0.693}{0.1989} \\
& \mathrm{t}_{1 / 2}=3.48 \mathrm{~min}
\end{aligned}$