COXDUCTANCE OF SODIUM CHLORIDE IN DIOXANE-WATER MIXTURES
April, 1963
911
CONDUCTANCE OF THE ALKALI HALIDES. V. SODIU&t CHLORIDE I N DIOXAKE-WATER AlIXTURES1p2 BY ROBERT W. KUNZEAND RAYMOXD &!t. Fuoss Contribution N o . i7gi from the Sterling Chemistry Laboratory of Yale University, New Haven, Connecticut Received October Si, 1968 The conductance of sodium chloride a t 25’ was measured in dioxane-water mixtures covering the range of dielectric constant 12.24 5 D 2 78.54. The Fuoss conductance equation reproduces the conductance as a function of concentration within the experimental error of O.Ol-O.O5% for concentrations where xa does not exceed 0.2. The contact distance d~ is 3.38 for aqueous solutions; it inereases to 5.33 at D = 12.24. The distance a K from the association constant also increases with decreasing dielectric constant.
I n this paper are presented the conductances of dilute solutions of sodium chloride in dioxane-water mixtures. As for potassium ~ h l o r i d ecesium ,~ i ~ d i d eand , ~ rubidium b r ~ m i d e the , ~ observed equivalent conductances A are accurately reproduced as a function of the coiicentration c by the equation6 A = A,
- XC‘/z y
1/2
+ ECYlog CY + JCY +
This equation contains three arbitrary coiistants, Ao, U J and K A , where U J IS an implicit function of the coefficient J in the present formulation of the theory. I n principle, it is also possible to derive values of the centerto-center contact distance from the limiting conductance’ AI, and from the association constant* K A . Denoting these distances by ah and ar
