For first order reactions:
K1t1=ln(11−23)=ln3 K_1 t_1 = \ln\left(\frac{1}{1 - \frac{2}{3}}\right) = \ln 3 K1t1=ln(1−321)=ln3
K2t2=ln(11−45)=ln5 K_2 t_2 = \ln\left(\frac{1}{1 - \frac{4}{5}}\right) = \ln 5 K2t2=ln(1−541)=ln5
∴K1t1=5andK2t2=2 \therefore K_1 t_1 = 5 \quad \text{and} \quad K_2 t_2 = 2 ∴K1t1=5andK2t2=2
K1K2=ln3ln5 \frac{K_1}{K_2} = \frac{\ln 3}{\ln 5} K2K1=ln5ln3
t1t2=0.4770.699×5=1.7×10−1 \frac{t_1}{t_2} = \frac{0.477}{0.699} \times 5 = 1.7 \times 10^{-1} t2t1=0.6990.477×5=1.7×10−1
For a first-order reaction, the concentration of reactant was reduced from 0.03 mol L−1^{-1}−1 to 0.02 mol L−1^{-1}−1 in 25 min. What is its rate (in mol L−1^{-1}−1 s−1^{-1}−1)?