THE FREE ENERGY OF HYDROCHLORIC ACID IN AQUEOUS SOLUTION. II

Arthur A. Noyes, James H. Ellis
1917 Journal of the American Chemical Society  
of KI, in that they first decrease slowly, pass through a minimum, and then increase rapidly. This result shows that the actual conditions are intermediate between those assumed in computing the constant K1 and the constant Kz, and makes it probable that the two complex acids H+BiCtand H+zBiC16' are both present in the solution. The HzBiC15 doubtless predominates in the more dilute solutions where there is a large excess of free hydrochloric acid,' and the HBiC14 in the more concentrated
more » ... concentrated solutions, where ultimately (in the last three solutions) there is not even enough chloride present to convert all the bismuth into the BiCl5' ion (since ZC1 is less than 5ZBi). Alkali salts of both of these complex acids have previously been separated from their solutions.2 Summgry. In this article have been presented measurements on the electrical conductance at 25' of solutions of bismuth chloride in aqueous hydrochloric acid. The results show that the conductance of this acid is considerably reduced by dissolving bismuth chloride in it, and indicate the formation of a complex acid of the form HBiCt or HzBiC16. Experiments on the solubility at 25 O of bismuth oxychloride in hydrochloric acid through a wide range of concentration have also been presented. The results considered from the mass-action standpoint are shown to be intermediate between those required by the assumption that the complex acid is HBiC14 and the assumption that it is H2BiC1S. The latter doubtless predominates in solutions containing a considerable excess of hydrochloric acid; and the former, in those in which this is not the case. CAMBRIDGE, MASS.
doi:10.1021/ja02257a004 fatcat:ggisut5gx5gdpezocpvc5xu4qy