The Viscosity and Conductivity of Aqueous Solutions of Electrolytes Mixed with Glycine and Urea

Abstract

of the strong electrolytes has been found to be greater than that of urea in the mixed solutions. The states of the hydration of glycine, urea and the strong electrolytes have been discussed on the basis of the relations between B-values in the viscosity formula of Jones and Dole and the effective volumes in aqueous solutions.Some studies of the electrochemical properties of aqueous solutions of strong electrolytes using several methods have been reported,1-4) but only a few data are available in the literature5-8) for aqueous solutions of mixed electrolytes. The purpose of the present study is to obtain some information concerning hydration and related problems, and to determine the behavior of weak electrolytes from measurements of the viscosity, density and conductivity of various electrolyte solutions in which weak electrolytes are mixed with strong electrolytes.In the present studies, glycine and urea9) were used as weak electrolytes, and potassium chloride and lithium chloride, as strong ones. An aqueous solution of potassium chloride has a negative viscosity coefficient, while that of lithium chloride is well known to have an abnormal concentration dependence of the viscosity. The viscosity coefficients and densities of aqueous solutions of electrolytes were measured over and appropriate concentration range. Their conductivities were also measured in order to compare the retarding effects of glycine on the mobility of ions with those of urea.The viscosity formula ofJones and Dole is:

Urea Facilitates the Translocation of Single-Stranded DNA and RNA Through the α-Hemolysin Nanopore

“…Effect of urea on the ionic current passing through the pore Urea has been reported to decrease the specific conductivity of aqueous solutions of potassium chloride (27,28). Accordingly, we found that the conductivity of buffers containing KCl (0.3, 0.5, and 1.0 M), 5 mM HEPES, pH 7.5, decreased linearly as a function of urea concentration at 4.8% M À1 (see Fig.…”

Solvation of Ions

“…Conductance measurements at 15°, 25°, and 35°C of aqueous solutions of KC1 and LiCl mixed with glycine or urea showed that the mechanism and state of hydration of the ions and solutes were the same in mixed solutions as in water [134].…”