Photochemical Interactions of Hydrogen with Chlorine and Bromine

Abstract

THE photochemical interaction of chlorine and hydrogen has been recently described as an inexhaustible theme. Despite the fact that it has been the subject of so many carefully performed experimental researches, it is not yet possible to describe the stages of transformation of the two gaseous elements into the compound hydrogen chloride. We have recently solved one of the outstanding difficulties. The rate of union of the corresponding reaction between hydrogen and bromine is nearly proportional to the square root of the intensity of the light, that is, to the light absorbed by the bromine in unit time, whereas determinations of the rate of union of chlorine and hydrogen have shown it to be almost directly proportional to the intensity of the light.