Détermination des pressions partielles du mélange eau-acide nitrique

Institut de Chimie, Université Louis Pasteur, 1, rue Blaise Pascal, 67008 Strasbourg.

Résumé

On montre que les différents résultats expérimentaux concernant les pressions partielles du mélange Η₂Ο — HNO₃, ne sont pas consistants entre eux. Une méthode simple est proposée qui permet de recalculer les pressions partielles et certaines fonctions thermodynamiques dans tout le domaine de concentration et pour des températures comprises entre — 10 et 70 °C.

Abstract

It is shown that the various experimental results concerning the partial pressures over Η₂Ο — HNO₃, mixtures fail to agree with one another. In particular, the results of the compilation by Taylor, which are tabulated in many reference books are shown to disagree with most of the other experimental determinations. In this work, using a compilation of all available results at 0 and 50 °C. and applying the method described by Aunis, the partial pressures of both water and nitric acid are determined in the whole range of concentration and for temperatures between — 10 and 70 °C. Also shown in figure 4 are the excess Gibbs free energy of mixing and the excess chemical potentials of H₂O and HNO₃, at 25 °C.