\(\mathrm{k}=\frac{1}{\mathrm{t}} \ln \left[\frac{\mathrm{A}_{\mathrm{o}}}{\mathrm{A}_{\mathrm{t}}}\right] \quad \begin{array}{ll}{\text { For } 99 \% \text { completion, }} \\ {[\mathrm{A}]_{\mathrm{o}}=100, \quad \mathrm{[A]}_{\mathrm{t}}=1}\end{array}\)

\(\mathrm{k}=\frac{1}{\mathrm{t}} \ln \left[\frac{100}{1}\right]\)

\(\mathrm{k}=\frac{2.303 \mathrm{log}_{10} 100}{\mathrm{t}}\)

\(\mathrm{k}=\frac{2.303 \times 2}{\mathrm{t}}\)

\(\mathrm{k}=\frac{4.606}{\mathrm{t}}\)

\(t=\frac{4.606}{k}\)