An accurate knowledge of the liquid viscosity is of fundamental importance in many scientific fields and industrial processes. Since, the measurement of viscosity values of liquids is based upon the absolute viscosity of freshly distilled water at 20℃ as a primary stand and, the establishment and preservation of viscosity measurement standards by using distilled water is required.
In this study, national of viscosity have been established as a function of salt concentration at 20.00℃ and 1 atm. Salts such as chloride salts or nitrate salts were selected because of their good solubility in water and some viscosity datas showing steep concentration dependence. When electrolyte is dissolved in pure water, the water structure may be expected to change by forming clusters around ions. As the concentration of ions is increased, therefore, number of clusters will increase and mobility of more number of water molecules will decrease to increase viscosity of water.
In order to explain the salt concentration dependence of water viscosity, it was assumed that aqueous solution of electrolytes is a mixture of pure water molecules and clusters of water molecules around ions. A model eguation based upon the free volume theory and absolute react ion rate theory was proposed by assuming that the ionic strength of electrolyte has an effect on the excess free energy of activation terms of the mixture equation.
