Evaluation of solubility and thermodynamic properties of synthetic nickel hydroxide carbonate

Abstract

Abstract Knowledge of the values of the thermodynamic functions of natural minerals of transition elements has important applications in the study of the processes of their formation and geochemical migration with groundwater; when developing methods to prevent corrosion of non-ferrous alloys in fresh and sea water; when immobilizing heavy metals in mine drainage and industrial waters, etc. Also, these values are in demand when calculating reactions and developing methods for producing synthetic analogues of minerals, many of which exhibit magnetic, catalytic, photochemical and other properties. A sample of basic nickel carbonate with the theoretical formula Ni3[СO3](OH)4·3H2O was obtained using the hydrothermal synthesis method. The structure of the compound was verified by X-ray diffraction and infrared spectroscopy. Experiments were carried out on sample dissolution in order to measure the solubility constant (solubility product): logKSP = − 45.8 ± 1.8. Based on the data obtained, the thermodynamic parameters of the reaction of dissolution of the compound were determined and the main thermodynamic functions were determined: Gibbs free energy of formation ΔfG°=−1554 ± 6 kJ/mol; enthalpy of formation ΔfH°=−1798 ± 9 kJ/mol; standard entropy S°=260.6 ± 7.8 J/(mol·K).