At t=0 butadiene was introduced into an empty vessel at 326 degree celsius and the gas phase dimerization reaction was followed at constant volume by monitoring the pressure P. find the reaction order using a Powell plot or the fractional-life method and also estimate the rate constant if The following data were obtained (1ks=10^3 s): t/ks 0.000 0.367 0.731 1.038 1.751 2.550 3.625 5.403 7.140 10.600P/torr 632.0 606.6 584.2 567.3 535.4 509.3 482.8 453.8 453.3 432.8