Volumetric and steric properties of hydroxamic acids in ethanol at different temperatures

Highlights: ► Density, ρ and refractive index, n of PBHA and o-TBHA are measured in ethanol at different temperatures. ► From the experimental value of ρ and n, Vφ, Vφ0, SV∗, φE0, V, RM, RS and α are calculated. ► Excess properties such as VE, RME, nE are also computed. ► The behaviour of these parameters suggests that PBHA and o-TBHA act as structure maker in ethanol. - Abstract: Physical properties, such as density, ρ and refractive index, n of two hydroxamic acids (N-Phenylbenzo, C6H5NOH·C6H5C=O and N-o-tolylbenzo, o-CH3·C6H4NOH·C6H5C=O) have been measured in ethanol as a function of concentration at T = (298.15, 303.15, and 308.15) K. The apparent molar volume, Vφ, apparent molar volume at infinite dilution, Vφ0 and the slope, SV∗ are calculated from the experimental value of density, ρ by applying the Masson's equation. The apparent molar expansibility at infinite dilution, φE0, molar volume, V and the excess molar volume, VE are also computed. The refractive index, n, data have been used to calculate the steric parameters viz. molar refraction, RM, excess refractive index, nE, excess molar refraction, RME and polarizability, α of these molecules. The results obtained have been qualitatively used to interpret the solute–solute and solute–solvent interactions between hydroxamic acids and ethanol.