Velocity Ultra Centrifuga Tion of Heteropol

The viscosity of iodine must be of the same order of magnitude as that of bromine and the same holds for solutions in the two solvents. The concentrations at which the minimum conductance appears would seem to indicate a dielectric constant markedly higher than that of bromine at 250. In benzene (D. const. = 2.28), the conductance minimum for a strong salt lies at 1 X 10-1 N; for anisole (D = 4.29), it lies at 1 X 10-3 and for ethylene bromide (D = 4.76), it lies at 5 X 10-3 N. On this basis, the dielectric constant of liquid iodine at 140°C. might be expected to lie in the neighborhood of 5.0. In any case, we cannot escape the conclusion that potassium iodide in iodine solution is very measurably dissociated into free ions at low concentrations and highly dissociated at higher concentrations. If we may be permitted to repeat, to gain an understanding of concentrated electrolytic solutions, we shall have to consider them from the point of view of solutions of solvent in salt. In solvents of low dielectric constant, the state of the system is determined by the charged ions of the electrolyte; the lower the dielectric constant, the lower the concentration down to which the ions are the dominant factor. 1 Darby, Edward H., J. Am. Chem. Soc., 40, 348 (1918). 2 Terwogt, P. C., Z. anorg. Chem., 47, 203 (1905). 3 Scott, A., J. Chem. Soc., 103, 347 (1913). 4 Strong, L. E., and Kraus, C. A., J. Am. Chem. Soc., 72, 166 (1950). 5Seward, R. P., Ibid., 73, 515 (1951). 6 Lewis, G. N., and Wheeler, P., Proc. Am. Acad., 41, 419 (1906).