Density, speed of sound and viscosity of calcium nitrate + water and + sucrose / + urea water mixtures

Abstract

Partial molar volume, ultrasonic speed and viscosity of aqueous solutions of calcium nitrate and sucrose/ urea-water mixtures of the same electrolyte have been measured at 303.15, 313.15, 323.15 and 333.15 K. In all the three media the apparent molar volume and the ultrasonic velocity increase with the molarity of calcium nitrate and the temperature. Viscosity B - coefficients show a positive concentration dependence in all the three media. They decrease in water and sucrose-water mixtures but increase in urea-water mixtures as the temperature increases. The solvation numbers of Ca²⁺increase with the concentration of urea or sucrose. All these parameters follow the order: sucrose-water> water> urea-water. Thus, the addition of sucrose enhances and urea subdues the water structure making due to Ca²⁺. This observation is in line with the accepted flickering cluster model of water.