# Determination of Volume Properties of Aqueous Vanadyl Sulfate at 283.15 to 323.15 K

journal contribution

posted on 30.04.2014, 00:00 by Wei-Guo Xu, Ye Qin, Fei Gao, Jian-Guo Liu, Chuan-Wei Yan, Jia-Zhen YangThis paper reports the densities
of aqueous VOSO

_{4}that were measured by an Anton Paar DMA 4500 M from 0.0500 mol·kg^{–1}to 3.000 mol·kg^{–1}at 283.15 to 323.15 K. The apparent molar volume,^{ϕ}*V*_{B}, the partial molar volume of VOSO_{4},*V̅*_{B}, the apparent molar expansibility of the solute, ϕ_{E}, and coefficient of thermal expansion of the solution, α, were calculated. First, these properties described above have been discussed with the temperature and concentration variation. Then the values of the apparent molar volume,^{ϕ}*V*_{B}, were fitted to Pitzer’s model for volumetric properties by the method of the least squares, which allowed the partial molar volume of the VOSO_{4}at infinite dilution,*V̅*_{B}^{0}, and Pitzer’s parameters, β_{MX}^{(0)V}, β_{MX}^{(1)V}, and*C*_{MX}^{V}, to be obtained. The small standard deviations of the fitting show that Pitzer’s model is also appropriate for representing the volumetric properties of aqueous solutions of VOSO_{4}. Using the data from literature, the partial molar volume of the ion VO^{2+}at infinite dilution,*V̅*_{C}^{0}, was discussed and the result showed that the negative value of*V̅*_{C}^{0}can be attributed to strong hydration of VO^{2+}as other divalent ions.