Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)




There has been much work done in the area of measurement of properties of dilute solutions. As a result, various relationships describing these properties have been observed. The region over which these relationships apply is narrow and limited to solutions of very low concentration. Some attempts have been made to extend these relationships to regions of greater concentration, but only limited success has been achieved. Most attempts are limited by insufficient knowledge of the properties of the concentrated solutions. The purpose of this research is to look at various properties of concentrated aqueous sodium and potassium hydroxide solutions and their mixtures. Because of research activity in the area, of alkaline batteries and fuel cells, more knowledge of the physical and chemical characteristics of those solutions at various temperatures is needed. Some work has been done in the area of equivalent conductance of these solutions. But to extend the to higher concentration, knowledge of the viscosity of these solutions is needed. Accurate viscosities of these solutions have been measured by determining the resistance of flow of these solutions in a small diameter tube (Ostwa1d viscometer). Differences in the two solute solutions were noticed, and the similarities and changes of the mixture solutions to the pure solute solutions were observed. From this investigation various relationships were tried, and new relationships proposed. The root equation for the concentration dependence of density was tried, and a new expression was proposed for concentrations expressed in mole fractions. Several concentration dependent equations for viscosity were tried, and most failed. As a result, modifications of existing theories were tried, and various degrees of success were achieved for both the viscosity of pure electrolytic solutions and solutions of mixed electrolytes. The existing temperature dependent equations for density proved to be adequate. A zero-mobility theory for the temperature dependence of viscosity and electrical conductance was tried, and some of the consequences of this theory were investigated.

Library of Congress Subject Headings

Sodium compounds
Potassium compounds
Electrolyte solutions



Number of Pages



South Dakota State University