For first order reactions:
\[ K_1 t_1 = \ln\left(\frac{1}{1 - \frac{2}{3}}\right) = \ln 3 \]
\[ K_2 t_2 = \ln\left(\frac{1}{1 - \frac{4}{5}}\right) = \ln 5 \]
\[ \therefore K_1 t_1 = 5 \quad \text{and} \quad K_2 t_2 = 2 \]
\[ \frac{K_1}{K_2} = \frac{\ln 3}{\ln 5} \]
\[ \frac{t_1}{t_2} = \frac{0.477}{0.699} \times 5 = 1.7 \times 10^{-1} \]
For a first-order reaction, the concentration of reactant was reduced from 0.03 mol L\(^{-1}\) to 0.02 mol L\(^{-1}\) in 25 min. What is its rate (in mol L\(^{-1}\) s\(^{-1}\))?