Modeling a Heterogeneous Cu(II)–H2O–OH––NH3 System with Data from Measuring pH

Abstract

A mathematical model of the Cu(II)–H2O–OH––NH3 system is developed using experimental data obtained by analyzing data on the residual concentration and pH, allowing determination of the conditions for the formation of copper compounds in a solution and in precipitated form. The solubility with respect to the intermediate and the rule for choosing the preferred precipitate are used in the model along with the rules of the product of solubility and molecular solubility to calculate regions of the formation of a solid phase. The values of the effective equilibrium constants of homogeneous and heterogeneous processes are calculated, using the proposed model for forty compounds formed in the system. In a number of cases, the compositions of the compounds are confirmed via X-ray fluorescence, X-ray diffraction, and differential thermographic analysis. It is established that in light of new theoretical concepts, the model allows the conditions for the hydrochemical synthesis of different target compounds to be optimized and provides a more efficient way of creating a database using the final experimental results.