Thermochimie

Abstract

THE science of thermochemistry owes most of its experimental data to the work of Thomsen, from 1853 onwards, in Copenhagen, and to the work of Berthelot in Paris from 1865. It was originally inspired by the idea that the amount of heat liberated in a chemical action was a measure of the energy available from this source, but this is only correct at the absolute zero; at all other temperatures, therefore, endothermic actions can occur, and it is no longer possible to predict from the thermochemical data alone in which direction a chemical action will proceed. On the experimental side also, the science has been limited by a standard of accuracy far lower than can be attained in other physical measurements. This lack of accuracy is the more to be deplored since the heats of formation of organic compounds are based upon the differences between relatively enormous heats of combustion; and the most interesting data {e.g. the heats of formation of isomers) contain even larger percentage errors than the heats of combustion through which they are determined.

Thermochimie.

Par Prof. F. Bourion. (Collection de Physique et Chimie.) Pp. xii + 363. (Paris: Gaston Doin, 1924.) 25 francs.