Abstract The apparent molar volume and apparent molar isentropic compressibility of solutions of sodium di-hydrogen phosphate (NaH2PO4) in (1-propanol + water) mixed-solvent media with alcohol mass fractions of 0.00, 0.05, 0.10, and 0.15 are reported over the range of temperature (283.15 to 303.15) K at 5 K intervals. The results were fitted to a Redlich–Mayer type equation from which the apparent molar volume and apparent molar isentropic compressibility of the solutions at the infinite dilution were also calculated at the working temperature. The results show a positive transfer volume of NaH2PO4 from an aqueous solution to an aqueous 1-propanol solution. The apparent molar isentropic compressibility of NaH2PO4 in aqueous 1-propanol solutions is negative and it increases with increasing the concentration of NaH2PO4, 1-propanol, and temperature. Electrical conductivity and refractive index of the solutions are also studied at T = 298.15 K. The effects of the electrolyte concentration and relative permittivity of the medium on the molar conductivity were also investigated.
