Evaluation of Thermo-Acoustical Parameters of Strong Electrolytesmetal Sulphates in Aqueous Medium at Different Temperatures

Values of ultrasonic velocity (U), density (d) and viscosity (η) have been measured in aqueous solutions of zinc sulphate and magnesium sulphate in different concentrations over the temperature range 298.15K to 313.15K at 5K interval. The thermo-acoustical parameters, such as acoustic impedance (Z), isentropic compressibility (K_s), apparent isentropic compressibility (K_s,φ), intermolecular free length (L_f), relative association (R_A), relaxation time (τ), Gibb's free energy change (ΔG), solvation number (S_n), ultrasonic attenuation (α/f²), internal pressure (π_i) and free volume (V_f) have been computed to assess the ion-solvent and ion-ion interactions in these solutions. It is found that the ion-solvent and ion-ion interactions depend on concentration, temperature, ionic size, ionic field strength and nature of the ion. The structural arrangement of molecules in electrolyte solutions has been discussed on the basis of electrostatic field (ionic field) of ion. The qualitative intermolecular elastic forces between the solute and solvent molecules are explained in terms of compressibility. The variation of solvation number with respect to temperature and concentration of electrolyte solution has been explained in the light of dipolar interaction between solute and solvent.