Conductometric and volumetric study of copper sulphate in aqueous ethanol solutions at different temperatures

Peer review under responsibility of Taibah University

Abstract

An Anton Par Model 55 densimeter was used to measure the densities of copper sulphate solutions in H₂O and EtOH–H₂O at 298.15 K, 303.15 K, 308.15 K, and 313.15 K. The acquired information was used to ascertain the apparent molar volumes, limiting partial molar volumes, and transfer partial molar volumes of copper sulphate. These computed parameters were utilized to decipher the solute–solute and solute–solvent interactions of copper sulphate in an aqueous ethanol solution. The ion solvation behavior of copper sulphate in water and aqueous ethanol over the range of 298.15–313.15 K was studied using the electrical conductivity principle. The Kraus–Bray and Shedlovsky models of conductivity were used to analyze the obtained conductance data. From the obtained data, the limiting molar conductance λ°_m, association constant K_A, energy of activation of the rating process (E_a), and related thermodynamic parameters were determined. The Walden product (λ°_mη₀) was determined. The standard thermodynamic parameters of association (ΔG°_A, ΔH°_A) were calculated and discussed. Increased ion–solvent and solvent–solvent interactions are indicated by limiting molar conductance values with an increasing amount of ethanol. The negative ΔG°_A values indicate that the association processes in all of the studied systems are spontaneous processes. The negative estimation of (ΔH°_A) demonstrates that the association processes is exothermic in nature.

Keywords:

• Partial molar volume
• Copper sulphate
• Binary mixtures
• Transfer volumes

Notes

Peer review under responsibility of Taibah University