Physico-chemical study of Dead Sea waters: II. Density measurements and equation of state of Dead Sea waters at 1 atm

The densities ( p) of artificial solutions of Dead Sea waters have been measured at 20°, 25°, 30°, 35° and 40°C using a vibrating tube densimeter. The resulting relative densities ( p — p o, where p o is the density of water) have been used to determine an equation of state for Dead Sea waters. The average deviation between experimental values and those calculated from the obtained equation was 0.000020 g ml −1. A thermal expansion coefficient and the coefficients characterizing the influence of the changes in salt or ionic concentrations on the density of Dead Sea waters were calculated, and they were shown to be temperature and concentration dependent. The densities of Dead Sea waters were found to be very sensitive to any changes in ionic composition. The partial molal volumes of salt components were calculated and discussed.