The homogeneous thermal decomposition of nitrous oxide

Abstract

The thermal decomposition of nitrous oxide was investigated by Hunter (‘Z. Physikal. Chem.,’ vol. 53, p. 441 (1905)), who used a streaming method. He found that bimolecular constants were obtained, but only followed the decomposition over small ranges and did not attempt to test whether the reaction were homogeneous or heterogeneous—nor did he work at pressures other than atmospheric. We wished to know definitely (1) whether the reaction is homogeneous, because true gaseous reactions are sufficiently rare to be of interest in themselves; (2) whether the reaction, if heterogeneous, is truly bimolecular, since this would be an interesting type of heterogeneous reaction, of which an example has not yet been found. It is notoriously difficult to place reliance in the constancy of "constants," and since Hunter’s constants were calculated in each case over a small range of decomposition only, we proposed to apply the more reliable criterion of varying the initial pressure considerably. An additional reason for not placing too much reliance on the velocity constant is given by Hunter's observation that by-products are formed as well as N 2 and O 2 .