Isotherms of hydrogen, of nitrogen, and of hydrogen-nitrogen mixtures, at 0° and 20° C., up to a pressure of 200 atmospheres

Abstract

Abstract From the work carried out and the statements made by several authors (cf. 10 of this paper) it seems that, in the case of mixtures of the “permanent” gases, the pv-values at normal temperatures should be linear functions of the composition. Since this assumption has been based principally upon the experimentally determined isotherms of air in relation to those of oxygen and nitrogen, it would appear desirable to investigate the mixtures of some other pair of gases, and for this purpose hydrogen and nitrogen have been selected. In the case of hydrogen, the determinations of isotherms which have been made at 0° and 20° C. by various authors are reasonably concordant, and probably represent a high degree of accuracy, but the agreement between the experimental isotherms of nitrogen leaves much to be desired. Moreover, no work whatsoever appears to have been published on the isotherms of hydrogen-nitrogen mixtures. Before proceeding to the description of the apparatus used in this research, a brief account and criticism of previous work will be given. This account deals only with modern determinations, and does not consider Amagat’s results, which were obtained at a time when the resources of modern technique were not available, and were published in such a form that a criticism of his results is scarcely possible.