Chemistry - Chemical Kinetics Question with Solution | TestHub

Concentration decreases by $90\%$. Hence, $10\%$ reactant is left after 30 minutes. $\begin{array}{rl}\mathrm{k}& =\frac{2.303}{\mathrm{t}}{\log }_{10}\frac{[\mathrm{A}{]}_0}{[\mathrm{A}{]}_{\mathrm{t}}}\\ \mathrm{k}& =\frac{2.303}{30}{\log }_{10}\frac{100}{10}\\ & =\frac{2.303}{30\min }\\ & =7.7\times 10^{-2}{\min }^{-1}\end{array}$