The accuracy of Senum and Yang's approximations to the Arrhenius integral

The accuracy of the integral of the Arrhenius equation, as determined from the 1(st) to the 4(th) degree rational approximation proposed by Senum and Yang, has been calculated. The precision of the 5(th) to 8(th) rational app roximations, here proposed for the first time, has also been analyzed. It h as been concluded that the accuracy increases by increasing the order of th e rational approximation. It has been shown that these approximations to th e Arrhenius equation integral would allow an accuracy better than 10(-8)% i n the E/RT range generally observed for solid state reactions. Moreover, it has been demonstrated that errors closed to 10(-2)% can be obtained even f or E/RT=1, provided that high enough degrees of rational approximation have been used. Thus, it would be reasonable to assume that high degree rationa l approximations for the Arrhenius integral could be used for the kinetic a nalysis of processes, like adsorption or desorption of gases on solid surfa ces, which can take place at low temperatures with very low Values of E/RT.