$\begin{aligned} & \mathrm{A}(\mathrm{g}) \rightarrow 2 \mathrm{~B}(\mathrm{~g})+\mathrm{C}(\mathrm{g}) \\ & \mathrm{P}_{23}=\mathrm{P}_0+2 \mathrm{x}=200 \\ & \mathrm{P}_{\infty}=3 \mathrm{P}_0=300 \\ & \mathrm{P}_0=100 \\ & \mathrm{~K}=\frac{1}{\mathrm{t}} \ln \frac{\mathrm{P}_{\infty}-\mathrm{P}_0}{\mathrm{P}_{\infty}-\mathrm{P}_{\mathrm{t}}} \\ & \mathrm{K}=\frac{2.3}{23} \log \frac{300-100}{300-200} \\ & =\frac{2.3 \times 0.301}{23}=0.0301=3.01 \times 10^{-2} \mathrm{sec}^{-1}\end{aligned}$