Integrated rate law equaiton for a first order gas phase reaction is given by (where P i is initial pressure P t is tota…

\(\mathrm{K}=\frac{2.303}{\mathrm{t}}\times \log \frac{{\mathrm{P}}_{\mathrm{i}}}{\left(2{\mathrm{P}}_{\mathrm{i}}−{\mathrm{P}}_{\mathrm{t}}\right)}\)

\(\mathrm{K}=\frac{2.303}{\mathrm{t}}\times \log \frac{2{\mathrm{P}}_{\mathrm{i}}}{\left(2{\mathrm{P}}_{\mathrm{i}}−{\mathrm{P}}_{\mathrm{t}}\right)}\)

\(\mathrm{K}=\frac{2.303}{\mathrm{t}}\times \log \frac{\left(2{\mathrm{P}}_{\mathrm{i}}−{\mathrm{P}}_{\mathrm{t}}\right)}{{\mathrm{P}}_{\mathrm{i}}}\)

\(\mathrm{K}=\frac{2.303}{\mathrm{t}}\times \log \frac{3{\mathrm{P}}_{\mathrm{i}}}{\left(2{\mathrm{P}}_{\mathrm{i}}−{\mathrm{P}}_{\mathrm{t}}\right)}\)