STUDY OF THE PROCESS OF COPPER(II) COMPLEXATION WITH N-ACETYLTHIOUREA IN AN ENVIRONMENT OF 4 MOl/l HCl AT 308K

The process of complex formation of copper (II) with N-acetylthiourea in a medium of 4 mol/l HCl at a temperature of 308 K was studied using a potentiometric method. A redox system based on N-acetylthiourea and its oxidized form was used as an electrode to determine the potential of the system, and reference electrode - silver chloride electrode. Studies have shown that when adding a solution of CuCl2·2H2O to solutions containing N-acetylthiourea and its oxidized form, the potential of the system increases. To determine the amount and stability of complex particles formed between copper (II) and N-acetylthiourea, the results of potentiometric titration were processed according to the Burrum method. At each titration point, the production function (ñ) and the equilibrium concentration of the organic ligand were determined. Processing of experimental data showed that the value of ñ varies from 0.38 to 4.04, which indicates stepwise complexation and combination of four molecules of the studied ligand with Cu(II). The values of the stability step constants decrease with increasing number of N-acetylthiourea molecules in the inner sphere of the complex. The thermodynamic functions of the processes of complex formation of copper (II) ions with N-acetylthiourea were calculated. The values of their formation constants are estimated. General patterns have been identified in the change in the values of the stability constants of the resulting complex particles depending on the nature of the organic ligand used, solvent concentration and temperature.