MARTINKILPATRICK AND MAXW. MEYER
0
Tal. 63
where the constants
and the concentrations of the third-bodies are included in the velocity constants. This has the solution
If - d[H]idt = 0 at t = 03. then (Ola)'/z= [HIe and (ab)'" = a [HI,. For the decay of the very small excesses we measured, it is also necessary to measure [HIe and treat the data in the following manner. Calculate and plot log { ([HI [€€],)/([HI - [HIe)] against t , which should be linear and of slope 0.868 a[HIe. Such a plot for a flame of mixture strength 1.35 and in which t has been calculated from experimental risevelocity measurements is shown in Fig. 4. In this case, the parameter a takes the value, 0.59 X 10-ls C M . ~ molecule-' set.-' at 2078°K. This is only somewhat lower than the wlue of the over-all recombination parameter 2.0 X measured by Padley and Sugden in Hzflames a t 2085°K. Furthermore, despite the fact that the measurement of a is subject to largest error in the lowest temperature flames where [HI- [HIe,.the set shown in Fig. 1 displays an increase in a as the temperature is lowered (1013 a takes the following values a t 2051") 0.69; 1934", 0.79; 1890", 1.11). This similar trend is found in Hz flame^,^ 4 and the rates of recombination measured here infer that excesses in H, OH and 0 do exist. We are indebted to the National Research Council of Canada for a grant in aid of this research and we are grateful to the Aluminium Laboratories, Ltd., Kingston, Ont., for gifts of graded aluminum particles.
+
4 6 8 10 12 Time (millisec.). Fig. 4.-The recombination rate of H excesses in a flame of pre-burnt ratio (propane/stoichiometric propane) = 1.35. Times are above the burner top. 2
H H
+H +X
k7
Hz k-
+X
(7)
7
+ OH + S SICs H z O + X
(8)
k- 8
with X being predominately H20, its efficiency 10 times that of either Hz or K2, are by far the most important removers of supra-equilibrium concentrations. It may be readily shown that
THE KIKETICS OF THE REACTIONS OF AROMATIC HYDROCARBONS IK SULFURIC ACID. 11. TOLUENE, THE XYLENES, PSEUDOCUMENE SKD HEMIMELLITENE BY hfA4RTINI
