Open AccessThe absorption of light by chlorine, bromine and their gaseous mixtures
Author(s) -
L. T. M. Gray,
D. W. G. Style
Publication year - 1930
Publication title -
proceedings of the royal society of london. series a, containing papers of a mathematical and physical character
Language(s) - English
Resource type - Journals
eISSN - 2053-9150
pISSN - 0950-1207
DOI - 10.1098/rspa.1930.0029
Subject(s) - chlorine , bromine , halogen , chemistry , absorption (acoustics) , photochemistry , optics , organic chemistry , physics , alkyl
The use of the halogens as light-filters offers many advantages over organic substances in that they are readily obtained in a pure state and, in the absence of impurities, should not be subject to any photochemical changes. The work described below was carried out at various dates prior to the end of 1928. It arose partly out of statements made by Allmand and by Weigert to the effect that the absorption of chlorine appeared to be dependent on the incident intensity and on the nature of the source of light, and partly out of the unexpected behaviour on illumination of a chlorine-bromine light-filter of the type described by Peskov (containing, however, an excess of liquid bromine).Chlorine . Details of the experiments referred to by Weigert were published later by Weigert and Nicolai. According to these authors, a 20-cm. cell with planeparallel ends containing chlorine, placed in a divergent beam of light, transmits a greater proportion of the energy (as measured by a hydrogen-chlorine actinometer) when in the narrowest part of the beam than when in the broadest. The ratio of the two incident intensities in the experiments referred to was as 16 to 1, and the result was ascribed to an effect of light intensity on the extinction of the gas.