Abstract
The solubility of NdPO4(c) was studied at 23±2 °C from both the over and undersaturation directions, with pH ranging from 0 to 9, P concentrations ranging from 0.0003 to 1.00M, and equilibration periods ranging from 6 to 57 days. Equilibrium was reached in <6 days. From the H+, Nd, and P concentrations in equilibrated solutions, the logarithm of the thermodynamic equilibrium constant for the reaction (NdPO4(c) ⇄ Nd3++PO4 3-) was calculated to be -24.65±0.23 and the value of the Pitzer ion-interaction parameter β(2)for Nd3+-H2PO4 - was determined to be -92.9. Predictions based on these thermodynamic quantities were in excellent agreement with the experimental data.
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Rai, D., Felmy, A.R. & Yui, M. Thermodynamic model for the solubility of NdPO4(c) in the aqueous Na+-H+-H2PO4–HPO42–OH–Cl–H2O system. Journal of Radioanalytical and Nuclear Chemistry 256, 37–43 (2003). https://doi.org/10.1023/A:1023339723535
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DOI: https://doi.org/10.1023/A:1023339723535