Viscosities of oxalic acid and its salts in water and binary aqueous mixtures of tetrahydrofuran at different temperatures

Relative viscosities for the solutions of oxalic acid and its salts, viz. ammonium oxalate, sodium oxalate and potassium oxalate, at different concentrations have been determined in water and in binary aqueous mixtures of tetrahydrofuran (THF) [5, 10, 15 and 20% by weight of THF] at 298,15 K, and in water and in 5% (w/w) THF + water at five different temperatures. The data have been evaluated using the Jones–Dole equation and the obtained parameters have been interpreted in terms of solute–solute and solute–solvent interactions. The activation parameters of viscous flow have been obtained which depicts the mechanism of viscous flow. The oxalic acid and its salts behave as structure breakers in water and in binary aqueous mixtures of THF.