$\mathrm{R}=8.314\; \mathrm{JK}^{-1} \mathrm{mol}^{-1}$
\(\mathrm{E_a}=0\)
\(\log \left(\frac{\mathrm{K}_{2}}{\mathrm{K}_{1}}\right)=0\)
\(\frac{\mathrm{K}_{2}}{\mathrm{K}_{1}}=10^{\circ}=1\)
\(\Rightarrow \mathrm{K}_{2}=\mathrm{K}_{1}\)
\(\mathrm{K}_{2}=1.6 \times 10^{6} \mathrm{s}^{-1}\) at \(400 \mathrm{K}\)