Physical properties, such as density, rho and refractive index, n of two hydroxamic acids (N-Phenylbenzo, C6H5NOH center dot C6H5C=O and N-o-tolylbenzo, o-CH3 center dot C6H4NOH center dot 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, V-phi, apparent molar volume at infinite dilution, V-phi(0) and the slope, S-V* are calculated from the experimental value of density, rho by applying the Masson's equation. The apparent molar expansibility at infinite dilution, phi(0)(E), molar volume, V and the excess molar volume, V-E are also computed. The refractive index, n, data have been used to calculate the steric parameters viz. molar refraction, R-M, excess refractive index, n(E), excess molar refraction, R-M(E) and polarizability, alpha of these molecules. The results obtained have been qualitatively used to interpret the solute-solute and solute-solvent interactions between hydroxamic acids and ethanol. (C) 2012 Elsevier Ltd. All rights reserved.