Open AccessThe determination of the heat of dissociation of fluorine and of the latent heat of vaporisation of lithium
Author(s) -
Manohar S. Desai
Publication year - 1932
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.1932.0067
Subject(s) - fluorine , dissociation (chemistry) , bromine , chlorine , chemistry , alkali metal , quartz , iodine , inorganic chemistry , thermodynamics , materials science , organic chemistry , composite material , physics
The heats of dissociation of chlorine, bromine, and iodine have been determined by thermal methods and estimated to be 58·9, 45·2 and 35·2 kilo-cals. respectively. But no data are yet known concerning the heat of dissociation of fluorine. It is very difficult to subject fluorine to the same treatment as Cl2 , Br2 and I2 (i. e ., heating to a high temperature in a sealed quartz bulb) owing to its extreme chemical reactivity, and hence no direct method of determining the heat of dissociation of fluorine has yet been devised. In the present paper I have determined it indirectly by interpretation of the absorption spectra of alkali fluorides (for the present only NaF and KF). A short theory of the experiment is given below.