The influence of hydrogen and deuterium on the thermal decomposition of diethyl ether in the low pressure region.

Abstract

Richards (1936) found from sound dispersion measurement that at ordinary temperatures, in exciting the lower vibrational states of ethylene, collisions between hydrogen and ethylene molecules were ten times as effective, and collisions between deuterium and ethylene molecules 1∙27 times as effective as collisions between ethylene molecules themselves. This meas that hydrogen is about eight times as effective as deuterium. The Specific effects of foreign gases in facilitating the interconversion of translational and vibrational energy as determined from measurements of the velocity of sound in the mixtures, have been explained by Franck and Eucken (1933) in terms of the chemical affinity between the colliding partners. This can however scarcely explain the results of Richards. The difference which he observed between hydrogen and deuterium seems to exclude any explanation for the superiority of hydrogen based on chemical affinity. The specific effect of hydrogen in activating molecules in unimolecular decompositions has been described in previous communications from this laboratory (Hinshelwood 1927; Hinshelwood and Askey 1927; Hinshelwood and Staveley 1936). The comparison of hydrogen with helium seemed to suggest that the difference could not be explained by differences of mass and velocity but rather by differing chemical properties. It seemed that the comparison of the effect of hydrogen with that of deuterium would provide significant information, and that the comparison with the results of Richards would be of interest.

A kinetic study of the decomposition of monomeric nitrosomethane

“…REACTION VESSEL (1) ; MIXED CARRIER GAS OF NITROGEN (2 1111T1) AND NITRIC OXIDE (2 IlKtl) For these runs the circulation capillary chosen gave reaction times in the region of 0.6 sec. However, we make no attempt to calculate velocity constants in these runs as the pressure in the reaction vessel is continuously changing due to removal of nitric oxide.…”

The Reactions of Methyl Radicals.

“…CH, Cunningham and Taylor (6) Gomer and Noyes (12) 25 20 Phibbs and Darwent (28) Thompson and Linnett (37) 37 25 Taylor and Rosenblum (35) Ethane................ Smith and Taylor (32) Isobutane.............. 5.9 Saunders and Taylor (31) Ethylene oxide......... Gomer and Noyes (12) evident from the fact that the fraction (C2He + JCH4)/CO rose above 1 at 250°C. The rates of reaction 22 found by different workers are in good agreement: thus at 182°C.…”

The Kinetics of Elementary Reactions of the Simple Hydrocarbons.

“…Further evidence for the chain character of a number of decomposition reactions is furnished by the work of Staveley and Hinshelwood (188b,189,190) and others (39,55,126,194). They found that while large amounts of added nitric oxide would catalyze the reactions, small amounts caused some inhibition.…”