Temperature dependence of density, conductance and viscosity of zinc sulphate and copper sulphate solutions in aqueous medium in the presence of maltose and sodium chloride

Density (rho), viscosity (eta) and molar conductance (Lambda(m)) for hepta-hydrated zinc suphate (ZnSO(4 center dot)7H(2)O) and penta-hydrated copper sulphate (CuSO(4 center dot)5H(2)O) have been measured in aqueous systems modified with maltose and sodium chloride at different temperatures (298.15, 303.15, 308.15 and 313.15 K). The above measured parameters were then employed to obtain apparent molar volume (phi(v)), relative viscosity (eta(rel)) and molar conductance (Lambda(m)). The apparent molar volume was fitted in Masson's equation, relative viscosity in Jones-Dole equation and molar conductance into Onsager's equation to obtain secondary thermodynamic functions including limiting apparent molar volume (phi(0)(v)), A and B coefficients of Jones-Dole equation and limiting molar conductance (Lambda(0)(m)). The effects of concentration and temperature on these parameters were studied and discussed in terms of ion-solvent and ion-ion interactions. The variation of ion-solvent and ion-ion interactions and Walden product (Lambda(0)(m)eta(0)) suggested structure-making nature of these electrolytes in aqueous systems modified with maltose and sodium chloride.