Physical properties of some molten hydrated calcium salts

Abstract

Density, conductivity, viscosity, refractive index and surface tension of molten hexahydrates of calcium salts of the type CaX₂ (X=CI, Br, I, NO₃, CNS) have been measured as a function of temperature. Both, the conductivity and fluidity exhibit non-Arrhenius temperature-dependence for all the systems, and have been described in terms of the equation,<BR><br> <i style="mso-bidi-font-style:normal">Y</i>(Ʌ, ϕ) = <i style="mso-bidi-font-style:normal">A</i>_Y exp [-<i style="mso-bidi-font-style: normal">B</i>_Y/(<i style="mso-bidi-font-style:normal">T-T</i>_0,Y)]

<br> <br> based on the cooperative rearrangement theory. The dependence of the parameters <i style="mso-bidi-font-style:normal">A</i>_Y, <i style="mso-bidi-font-style: normal">B</i>_Y and <i style="mso-bidi-font-style:normal">T</i>_0,Y on the proton capturing power of the anions has been discussed. The correlation observed between <i style="mso-bidi-font-style:normal">T</i>₀ (or <i style="mso-bidi-font-style:normal">T</i>_g) with the strengths of the acids of the anions indicates the tendency of the anions to bind to the proton of the water molecules already associated with the cation sheath.