Thermodynamic study of (b1RbCl + b2MeCl2)(aq), where b denotes molality and Me denotes Mn, Co, Ni, or Cu, at the temperature 298.15 K, on the basis of Pitzer's model

✍ Scribed by Christomir Christov

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 271 KB
• Volume: 26
• Category: Article
• ISSN: 0021-9614
• DOI: 10.1006/jcht.1994.1125

✦ Synopsis

The molalities (b) of (\left{b_{1} \mathrm{RbCl}+b_{2}\left(\mathrm{CoCl}{2}\right.\right.) or (\mathrm{NiCl}{2}) or (\left.\left.\mathrm{CuCl}{2}\right)\right}(\mathrm{aq})), have been investigated in saturated solutions at the temperature (T=298.15 \mathrm{~K}) by the physicochemical-analysis method. The thermodynamic functions needed for theoretical plotting of the solubility isotherms are calculated using Pitzer's model. The results obtained are in good agreement with experiment, allowing conclusions to be drawn on the applicability of the thermodynamic method chosen for a sufficiently exact description of the properties of the ternary solutions investigated. The standard molar Gibbs free energies of reaction (\Delta{\mathrm{r}} \mathrm{G}{\mathrm{m}}^{\mathrm{o}}) of the synthesis of the double salts crystallizing from simple salts and their standard molar Gibbs free energies of formation (\Delta{\mathrm{f}} G_{\mathrm{m}}^{\circ}) are determined:

(\mathrm{RbCl} \cdot \mathrm{CoCl}{2} \cdot 2 \mathrm{H}{2} \mathrm{O})

(2 \mathrm{RbCl} \cdot \mathrm{McCl}{2} \cdot 2 \mathrm{H}{2} \mathrm{O})

(2 \mathrm{RbCl} \cdot \mathrm{CoCl}{2} \cdot 2 \mathrm{H}{2} \mathrm{O})

(2 \mathrm{RbCl} \cdot \mathrm{NiCl}{2} \cdot 2 \mathrm{H}{2} \mathrm{O})

(2 \mathrm{RbCl} \cdot \mathrm{CuCl}{2} \cdot 2 \mathrm{H}{2} \mathrm{O})

(\approx 0.00)

(-13.88)

(-3.79)

(-20.25)

(-1491.7)