For a first order reaction, $\mathrm{t}_{50}$ : $\mathrm{t}_{90}$ is equal to\

Question

Professor PC Thomas Classes · Answer

$\mathrm{t}_{50 \%}=\frac{2.303}{\mathrm{k}} \log \frac{100}{50}$\ $\mathrm{t}_{90 \%}=\frac{2.303}{\mathrm{k}} \log \frac{100}{10}$\ ratio $\frac{t_{50}}{t_{90}}=\frac{\log 2}{\log 10}=0.3=\frac{3}{10}$\