Vol. 64
GORDOSB. SKINNER ASD EDWAIW 11.SOKOLOYKI
1028
relationship of k2 to rl near 500°11., and this relationship is retained in our values. Similarly, our constants preserve the relation between T ~ and r1 established by Majury and Steacie13 near 500"K., and the value of klz found by Berlie and Le Royi4near 400°K. In addition to reproducing our om n kinetic data, the constant? of Table I V correlate with other data a t lower temperatures, as shown in Fig. 1. The curve was calculated by the steady-state method. Also, the net rate of production of CzH4 (but not of CHI) is zero when equilibrium concentrations of C2He.C2H4and Hz are used. One notable discrepancy between theory and 8 9 10 11 12 experiment remains. The free radical mechanism 1 0 4 / ~ OK. , predicts that the over-all reaction order should be Fig. l.---Init,ial rate of ethane pyrolysis: 0, this research, one-half a t lower temperatures, while first-order 0.3 at.m.; A , 1)avis and \Villia,mson, 1.0 at,m.; 0, Kuchler and Theile, 0.5 atm.; X, Steacie and Shane, 0.5 atm.; kinetics actually have been found over the whole temperature range. -, calculated, I .0 at,m. Acknowledgment.-The authors literature values, modified to fit, the over-all J t r . Edward 11. Sokoloski for hii thermodynamic and kinetic relationships. The both experiments and cnlculationb. negative t,emperature dependence of r1 has been (12) 4 r Trotman-Dlchenson I. R Rirchard and E W R Steacie. establishcd by Ingold and Lossing. l 1 TrotmanDickenson, Birchard and SteacieI2 studied the abid 19, 163 (1951)
-
(1 1)
Z
N
I
